OSWER Directive No. 9355.4-28
GUIDANCE FOR MONITORING
AT HAZARDOUS WASTE SITES:
FRAMEWORK FOR
MONITORING PLAN DEVELOPMENT AND IMPLEMENTATION
January 2004
-------
ACKNOWLEDGEMENTS
The authors wish to acknowledge all the reviewers that have assisted the authors
with constructive comments and assistance. We also wish to acknowledge the assistance
of the Argonne National Laboratory Environmental Assessment Division task leader, Dr.
Ihor Hlohowskyj, and the editorial assistance of the Argonne National Laboratory
Information Publishing Division, especially primary editor Patricia Hollopeter and the
staff of the Document Processing Center. We further wish to acknowledge the
Monitoring working group members that assisted in the development of this guidance.
Bethany Grohs, V.M.D.
Environmental Response Team
Office of Superfund Remediation and Technology Innovation
U.S. Environmental Protection Agency
EPA Working Group Members:
Clarence Callahan, Ph.D., Region IX
James Chapman, Ph.D., Region V
Bruce Duncan, Ph.D., Region X
Stiven Foster, ORD
Bruce Pluta, Ph.D., Region III
Patti Tyler, Region VIII
Other Working Group Members:
Amy Hawkins, Naval Facilities Engineering Service Center
Jody Wireman, Ph.D., MSPH, CIH, U.S. Air Force
-------
EXECUTIVE SUMMARY
This guidance document presents a framework for developing and implementing
technically defensible Monitoring Plans for hazardous waste sites. In support of the One
Hazardous Waste Cleanup Program, this document was written in direct response to, and for, site
managers who are legally responsible for managing removal and remedial site activities. It is
intended for use at hazardous waste sites that have completed site characterization, risk
assessment, and remedy selection and are in the process of implementing a removal action or site
mitigation.
This guidance presents a six-step framework for developing and documenting a
Monitoring Plan that will support management decisions. The framework includes the
identification of monitoring objectives and development of monitoring hypotheses to focus the
monitoring program, and the development of decision rules (exit criteria) that include action
levels and alternative actions for terminating or continuing the site activity and/or its monitoring
program.
Within the framework, Steps 1 through 3 document the logic and rationale of the
monitoring program by developing monitoring objectives that are directly related to the
objectives of the site activity and by developing decision rules that will support site management
decisions. Steps 4 through 6, which include the development of a Monitoring Quality Assurance
Project Plan (QAPP), ensure that this logic is maintained by focusing data needs and data
collection and analysis methods to directly support the monitoring objectives, decision rules, and
subsequent management decisions. The framework is iterative and allows for the evaluation of
the monitoring data as they are generated, thus supporting adaptive management of the site
activity and the monitoring program.
This guidance document is not intended to specify the scale, complexity, protocols, data
needs, or investigation methods for meeting the needs of site-specific monitoring. Rather, it
presents a framework that can be used to develop and implement scientifically defensible and
appropriate monitoring plans that promote national consistency and transparency in the
decision-making process. This guidance is fully consistent with the Agency-Wide Quality
System and may be adapted to meet the regulatory requirements of other U.S. Environmental
Protection Agency programs.
-------
IV
-------
CONTENTS
EXECUTIVE SUMMARY iii
LIST OF EXAMPLES, FIGURES, HIGHLIGHTS, AND TABLES vii
LIST OF ACRONYMS AND ABBREVIATIONS viii
INTRODUCTION: GUIDANCE FOR MONITORING AT HAZARDOUS
WASTE SITES Intro-1
PURPOSE Intro-1
SCOPE Intro-1
REQUIREMENTS FOR MONITORING Intro-2
OVERVIEW OF MONITORING Intro-3
MONITORING PLAN DEVELOPMENT Intro-4
STEP 1: IDENTIFY MONITORING OBJECTIVES 1-1
1.1 MONITORING OBJECTIVES 1-1
1.1.1 Examination of the Site Activity 1-1
1.1.2 Identify Monitoring Objectives 1-3
1.2 STAKEHOLDER INPUT 1-4
1.3 SCIENTIFIC MANAGEMENT DECISION POINT 1-4
STEP 2: DEVELOP MONITORING PLAN HYPOTHESES 2-1
2.1 MONITORING HYPOTHESES 2-1
2.2 MONITORING CONCEPTUAL MODEL 2-1
2.3 SCIENTIFIC MANAGEMENT DECISION POINT 2-1
STEP 3: FORMULATE MONITORING DECISION RULES 3-1
3.1 MONITORING DECISIONS 3-1
3.1.1 Formulation of Preliminary Decision Rules 3-1
3.1.2 Refinement of the Decision Rules 3-2
3.2 SCIENTIFIC MANAGEMENT DECISION POINT 3-3
STEP 4: DESIGN THE MONITORING PLAN 4-1
4.1 IDENTIFY DATA NEEDS 4-1
4.1.1 Expected Outcome of the Site Activity 4-1
4.1.2 Data Characteristics 4-2
4.1.3 Evaluate Applicability of Previous Investigations 4-2
4.2 DETERMINE MONITORING BOUNDARIES 4-2
4.3 IDENTIFY DATA COLLECTION METHODS 4-5
4.4 IDENTIFY DATA ANALYSIS METHODS 4-5
4.4.1 Descriptive and Inferential Statistics 4-6
4.4.2 Trend Analysis 4-7
4.5 UNCERTAINTY ANALYSIS 4-7
-------
4.6 FINALIZE THE MONITORING PLAN 4-8
4.6.1 Optimize the Design 4-8
4.6.2 Prepare Monitoring Quality Assurance Project Plan 4-9
4.7 SCIENTIFIC MANAGEMENT DECISION POINT 4-10
STEP 5: CONDUCT MONITORING ANALYSIS AND CHARACTERIZE
RESULTS 5-1
5.1 DATA COLLECTION AND ANALYSIS 5-1
5.2 EVALUATION OF ANALYTICAL RESULTS 5-1
5.2.1 Relationship of Analytical Results to the Monitoring Hypotheses 5-3
5.2.2 Data Adherence to the Data Quality Objectives 5-3
5.2.3 Data Support of the Decision Rules 5-4
5.3 ADDRESSING DATA DEVIATIONS FROM THE MONITORING DQOs... 5-4
5.3.1 Evaluating the Site Activity 5-4
5.3.2 Evaluating Implementation of the Monitoring Plan 5-5
STEP 6: MANAGEMENT DECISION 6-1
6.1 MANAGEMENT DECISIONS IN THE MONITORING PLAN 6-1
6.2 GENERAL MANAGEMENT DECISIONS 6-1
6.2.1 Monitoring Results Indicate Site Activity Is Successful 6-3
6.2.2 Monitoring Results Indicate Site Activity Trending Toward Success 6-3
6.2.3 Monitoring Results Indicate Site Activity Is Unsuccessful 6-3
6.3 DOCUMENTATION AND SCIENTIFIC MANAGEMENT
DECISION POINT 6-4
6.3.1 Conclude Site Activity and Monitoring 6-4
6.3.2 Continue Site Activity and Monitoring 6-5
6.3.3 Revise Site Activity 6-6
BIBLIOGRAPHY Bibliography-1
GLOSSARY Glossary-1
VI
-------
LIST OF EXAMPLES, FIGURES, HIGHLIGHTS, AND TABLES
List of Examples
I-1 Integration of Data Quality Obj ectives into Development of Monitoring
Plans, Verifying Success of Hypothetical Bioremediation and Habitat
Mitigation Activities Intro-8
1-1 Activity Outcome and Monitoring Objectives 1-2
2-1 Monitoring Remediation Success 2-2
2-2 Monitoring Habitat Mitigation Success 2-3
3-1 Preliminary Decision Rules for a Bioremediation Project 3-2
4-1 Hypothesis Testing and Type I and Type II Errors 4-6
5-1 Revising the Site Activity 5-5
5-2 Revising Implementation of the Site Activity 5-5
5-3 Revising the Sampling Regime 5-6
List of Figures
I-1 Six-Step Process for Developing and Implementing a Monitoring Plan Intro-6
5-1 Decision Path during Monitoring Implementation and Data Collection
and Analysis 5-2
6-1 Monitoring Outcome Management Decision Path 6-2
List of Highlights
1-1 Site Activities Intro-3
List of Tables
1.1 Example Monitoring Objectives for Different Site Activities 1-4
4-1 Potential Applicability of Previous Site Investigations to the Monitoring Design 4-3
6-1 Management Decision Documentation 6-5
vn
-------
LIST OF ACRONYMS AND ABBREVIATIONS
BRA baseline risk assessment
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
COC contaminant of concern
CSM conceptual site model
DQA data quality assessment
DQO data quality obj ective
ft foot (feet)
ICAP Induction Coupled Argon Plasma spectrometry
in. inch(es)
m meter(s)
NCP National Oil and Hazardous Substances Pollution Contingency Plan
OSC On-Scene Coordinator
ppb part(s) per billion
ppm part(s) per million
QA quality assurance
QAPP Quality Assurance Project Plan
QC quality control
RCRA Resource Conservation and Recovery Act
RI remedial investigation
ROD Record of Decision
RPM Remedial Project Manager
SMDP Scientific Management Decision Point
U.S.C. United State Code
U.S. EPA U.S. Environmental Protection Agency
XRF x-ray fluorescence
vm
-------
INTRODUCTION:
GUIDANCE FOR MONITORING AT HAZARDOUS WASTE SITES
PURPOSE
This guidance document presents a framework for developing and implementing
technically defensible Monitoring Plans for hazardous waste sites. In support of the One
Hazardous Waste Cleanup Program, this document was written in direct response to, and for, site
managers (i.e., On-Scene Coordinators [OSCs] and Remedial Project Managers [RPMs]) who
are legally responsible for managing removal and remedial site activities. However, risk
assessors supporting Comprehensive Environmental Response, Compensation, and Liability Act
of 1980 (CERCLA) and Resource Conservation and Recovery Act of 1976 (RCRA) activities
may also use this document. Specifically, the purposes of this guidance are to:
1. Provide a framework for the development and implementation of scientifically
defensible Monitoring Plans;
2. Facilitate consistency of monitoring across U.S. Environmental Protection
Agency (U.S. EPA or the Agency) regions and programs; and
3. Establish procedures for identifying decision criteria prior to data collection.
The policies and procedures described in this document are intended solely as guidance.
The statutory provisions and U.S. EPA regulations described in this document contain legally
binding requirements. This document is not a regulation itself, nor does it change or substitute
existing provisions and regulations. Thus, it does not impose legally binding requirements on the
U.S. EPA, States, Tribes, or the regulated community. This guidance does not confer legal rights
or impose legal obligations upon any member of the public.
The general guidelines provided in this document may not apply to a particular situation
based upon the circumstances. Interested parties are free to raise questions and objections about
the substance of this guidance and the appropriateness of the application of these guidelines to a
particular situation. The U.S. EPA and other decision makers retain the discretion to adopt
approaches on a case-by-case basis that differ from those described in this guidance where
appropriate.
This is a living document and may be revised periodically without public notice. The
U.S. EPA welcomes public input on this document at any time.
SCOPE
The U.S. EPA conducts monitoring activities under many different programs
(e.g., Superfund [SF], RCRA, Federal Facilities, and Underground Storage Tanks [USTs]), and
the monitoring framework presented in this guidance describes a process that can be adapted to
Intro-1
-------
meet the regulatory requirements of these programs. Each program office may also have
program-specific technical references (on data collection methods, data analysis, etc.) that may
be utilized in concert with the monitoring framework. In addition, these program offices fully
comply and are consistent with the Agency-Wide Quality System described in U.S. EPA
Order 5360.1A2 (U.S. EPA 2000c). The U.S. EPA Quality Manual for Environmental
Programs-5360 Al (U.S. EPA 2000b) provides the program requirements for implementing the
Agency-Wide Quality System. This monitoring guidance is fully consistent with these
requirements and the quality system. This monitoring guidance is intended for use at hazardous
waste sites that have completed site characterization, risk assessment, and remedy selection and
are in the process of implementing a remedial action or site mitigation.
This guidance document is not intended to specify the scale, complexity, protocols, data
needs, or investigation methods for meeting the needs of site-specific monitoring. Rather, it
presents a framework that can be used to develop and implement scientifically defensible and
appropriate Monitoring Plans that promote national consistency and transparency in the decision-
making process.
REQUIREMENTS FOR MONITORING
CERCLA statutory authority regarding monitoring gives the U.S. EPA authority to
undertake monitoring to identify threats [42 U.S.C. § 9604(b)] and defines removal and remedial
actions as inclusive of any monitoring reasonably required to ensure that such actions protect the
public health, welfare, and the environment [42 U.S.C. § 9601(23) and 42 U.S.C. § 9601(24)],
respectively. Section 121(c) of CERCLA [42 U.S.C. § 9621(c)], as amended by the Superfund
Amendments and Reauthorization Act (SARA) of 1986, together with the implementing
regulation in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP),
requires that "if the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site," post-response reviews be conducted every
5 years to ensure protection of human health and the environment. The NCP states that the focus
of the 5-year review should be review of monitoring data to evaluate whether the remedy
continues to provide for adequate, risk-based protection of human health and the environment
(40 CFR § 300.430 (f)(4)(ii)(2002)).
U.S. EPA policy for Record of Decision (ROD) development states that the lead agency
can require monitoring to verify that no unacceptable exposures to potential hazards posed by
site conditions will occur in the future. In corrective actions conducted under RCRA, as
amended, properly designed performance monitoring programs are considered integral to remedy
success and are to be considered throughout the corrective action process (U.S. EPA 1996).
Detailed guidance regarding RCRA performance monitoring is available in U.S. EPA 1992 and
200la. Additional monitoring regulations in support of RCRA include those pertaining to
groundwater and landfill standards. 40 CFR 264.90 (f), 264.98, and 265 delineate detection
monitoring requirements and monitoring system specifications for groundwater. 40 CFR 258.54
and 258.55 delineate detection and assessment monitoring program requirements for landfills.
Intro-2
-------
OVERVIEW OF MONITORING
Definition
The scientific literature provides a variety of definitions of monitoring. Among these, the
definition presented by Elizinga et al. (1998) most closely approximates monitoring at hazardous
waste sites: "The collection and analysis of repeated observations or measurements to evaluate
changes in condition and progress toward meeting a management objective." Within this
definition, monitoring is driven by management objectives and is implemented within a
management context. For example, monitoring under CERCLA may have the objectives of
collecting and evaluating data to determine whether the selected remedy meets the CERCLA
management objective of providing adequate risk-based protection of human health and the
environment.
Monitoring is the collection and analysis of data (chemical, physical, and/or biological)
over a sufficient period of time and frequency to determine the status and/or trend in one or more
environmental parameters or characteristics. Monitoring should not produce a "snapshot in time"
measurement, but rather should involve repeated sampling over time in order to define the trends
in the parameters of interest relative to clearly defined management objectives. Monitoring may
collect abiotic and/or biotic data using well-defined methods and/or endpoints. These data,
methods, and endpoints should be directly related to the management objectives for the site in
question.
Monitoring and Its Objectives
Many types of monitoring may be conducted at a site, such as detection monitoring
(to detect changes in ambient conditions), compliance monitoring (to evaluate compliance with
regulatory requirements), and remedial monitoring (to evaluate remedy effectiveness).
Depending on the nature of the site, one or more types of monitoring may be necessary and each
type will have its own monitoring objectives.
As previously stated, the objectives of a Monitoring Plan will depend directly on the
specific site activity and associated management objectives. Monitoring objectives may therefore
address the following:
• Evaluation of remedy effectiveness and protection of human health and the
environment;
• Evaluation of contaminant migration;
• Evaluation of effectiveness of habitat mitigation; or
Compliance with regulatory requirements.
Intro-3
-------
At a project location, the monitoring,
objectives and study design may also vary, depending
on the physical, chemical, and biological nature of the
site (such as a freshwater polychlorinated biphenyl
compound [PCB] site, a soil lead site, or a prairie
restoration site). In all instances, the associated number of activities that could
Monitoring Plan objectives ultimately should support occur at a hazardous waste Slte>
a management objective for the site and its activity.
Monitoring Outcome
HIGHLIGHT 1-1
Site Activities
Site activities may include any
including, but not limited to,
implementation and/or opera-
tion of a removal action,
remedial action, institutional
controls, or habitat mitigation.
Upon completion of the specified monitoring
activities, the results normally will point toward one
of three general conclusions, which in turn should be used to support a management decision for
the site. These conclusions will typically be related to the success of the site activity being
addressed by the Monitoring Plan. First, if the monitoring results indicate that the site activity
has been successful, the management decision may be to terminate monitoring and the site
activity and proceed with the relevant regulatory process or program under which the site activity
is being conducted. For example, CERCLA and the NCP require 5-year reviews conducted in
perpetuity whenever contaminants remain in place. This regulation remains regardless of the
outcome of the Monitoring Plan. Second, if the monitoring data indicate that the activity is
trending toward success, then the decision may be to continue monitoring. Finally, if the
monitoring data do not indicate activity success, clearly show activity failure, or are equivocal,
the management decision may be to evaluate both the site activity and the Monitoring Plan to
determine the factors responsible for the monitoring results, and to revise the Monitoring Plan
and/or the site activity accordingly. Management decisions may also be made earlier during
monitoring (e.g., prior to conclusion of monitoring) as monitoring data are generated. These
decisions may be to terminate the monitoring process sooner than planned, continue monitoring
as planned, or modify the monitoring program to guide ongoing activities toward their eventual
success.
MONITORING PLAN DEVELOPMENT
Monitoring Team Formation
The overall site decision rests with site management (e.g., the OSC and RPM). In order to
assist management with the development and implementation of a Monitoring Plan, a monitoring
team may be formed. This team may include the site manager, supporting technical staff
(e.g., Biological Technical Assistance Groups [BTAGs], risk assessors, analytical chemists,
environmental engineers), and appropriate stakeholders (e.g., natural resource trustees and the
public). The role of this team is to provide input into the development and implementation of the
Monitoring Plan. The formation of the team, as well as its involvement in the Monitoring Plan, is
site-specific and as requested, and/or directed by, site management.
Intro-4
-------
Process for Developing the Monitoring Plan
This guidance document presents a six-step
process that can be used to develop clear-cut monitoring
objectives; develop scientifically defensible study
designs and data interpretation methods; and support
management decisions based on decision criteria for
continuing, revising, or concluding monitoring and site
activities. This six-step process (depicted in Figure 1-1)
may be utilized to develop Monitoring Plans for various
types of monitoring, including but not restricted to those
intended to evaluate remedy effectiveness and habitat
mitigation. This process may also be employed to
develop a Monitoring Plan for conducting 5-year
reviews at sites where, upon completion of remedial
activities, some form of restricted land use remains.
Framework Scientific
Management Decision Points
(SMDPs)
Step 1: Monitoring objectives
Step 2: Monitoring hypotheses,
questions, and conceptual site
models
Step 3: Preliminary decision rules
Step 4: Monitoring QAPP
Step 5: Revisions to the Monitoring
Implementation Plan
Step 6: Decision Document
This guidance focuses on the components critical to developing a Monitoring Plan with
clearly identified and appropriate objectives, methods, and decision criteria. This guidance does
not provide recommendations on individual data collection methods, analyses, or other data
collection and analysis aspects of monitoring. The selection of specific data collection and
analysis methods, which occurs within Step 4 of this monitoring framework, would occur on a
site-specific basis and follow the procedures and requirements specified in the U.S. EPA Quality
Manual (U.S. EPA 2000b). The monitoring guidance calls for the development of a monitoring-
specific Quality Assurance Project Plan (QAPP) that is consistent with and satisfies the
requirements of the U.S. EPA Agency-Wide Quality System (U.S. EPA 2000c). The Monitoring
Plan must also identify the monitoring-specific quality assurance (QA) and quality control (QC)
policies and procedures (as identified in Chapter 5 of the U.S. EPA Quality Manual [U.S. EPA
2000b]) needed to achieve the monitoring objectives.
At the conclusion of each step of the six-step process, a scientific management decision
point (SMDP) occurs. These SMDPs serve as points in the process where decisions are
documented with regard to the Monitoring Plan objectives, hypotheses, study design, and,
ultimately, the management decision. Depending on the specific step in the process, formal
documentation of the SMDP may or may not be appropriate.
The development of a Monitoring Plan may go through one or more iterations, especially
involving Steps 2 through 4. For example, development of the Monitoring QAPP may show that
using the monitoring hypotheses and decision rules developed in Steps 2 and 3 result in a
Monitoring Plan that is too expensive to implement, for which resources are not available, or too
difficult to implement. In this case, one should return to Step 2 and see if the monitoring team
can revise the current hypotheses or develop alternative monitoring hypotheses and decisions.
Intro-5
-------
Step 1. Identify Monitoring Plan Objectives
• Evaluate the site activity
- Identify the activity objectives
- Identify the activity endpoints
- Identify the activity mode of action
• Identify monitoring objectives
• Stakeholder input
• Scientific Management Decision Point (SMDP)
Step 2. Develop Monitoring Plan Hypotheses
Develop monitoring conceptual models
Develop monitoring hypotheses and questions
SMDP
Step 3. Formulate Monitoring Decision Rules
Formulate monitoring decision rules
SMDP
Step 4. Design the Monitoring Plan
• Identify data needs
• Determine Monitoring Plan boundaries
• Identify data collection methods
• Identify data analysis methods
• Finalize the decision rules
• Prepare Monitoring Quality Assurance Project Plan
• SMDP
Step 5. Conduct Monitoring Analyses
and Characterize Results
Conduct data collection and analysis
Evaluate results per the monitoring DQOs (developed in Steps 1^1), and
revise data collection and analysis as necessary
Characterize analytical results and evaluate relative to the decision rules
SMDP
Step 6. Establish the Management Decision
Monitoring results support the decision rule for site activity success
- Conclude the site activity and monitoring
Monitoring results do not support the decision rule for site activity success
but are trending toward support of the decision rule
- Continue the site activity and monitoring
Monitoring results do not support the decision rule and are not trending
toward support
- Conduct causative factor and uncertainty analysis
- Revise site activity and/or Monitoring Plan and implement
SMDP
Figure 1-1 Six-Step Process for Developing and Implementing a
Monitoring Plan
Intro-6
-------
Use of the Data Quality Objectives Process
The six-step process for developing Monitoring Plans presented in this guidance relies
heavily on the use of the data quality objective (DQO) process (U.S. EPA 2000a). Use of a
systematic planning process such as the DQO process is a fundamental component of the
U.S. EPA Agency-Wide Quality System (U.S. EPA 2000c) and associated QA/QC guidance and
requirements (U.S. EPA 2000a-d; 2001b; 2002). Use of the DQO process produces qualitative
and quantitative statements that define the type, quality, and quantity of data necessary to support
a defensible monitoring decision by management. The DQOs identify when and where to collect
monitoring samples, the number of samples to be collected, how the samples should be analyzed,
the analytical performance criteria that need to be met, how the results should be interpreted
relative to the monitoring objectives, the practical constraints for collecting the samples, and the
level of uncertainty that is acceptable to the decision maker with regard to making a monitoring
decision.
The DQO process consists of seven sequential steps that lead to the development of an
optimized data collection plan. In the DQO process, the output of each step serves as input for
the next step. The process may be iterative, with the output of one step resulting in the
reconsideration of earlier steps.
Use of the DQO process improves project planning efficiency by promoting positive
communication among stakeholders, focusing the Monitoring Plan on a clear action-oriented
decision, and ensuring that decisions are made with a desired level of confidence in the results.
Use of the DQO process also provides a record of what data are needed before data collection
begins and the rationale for needing that data, thus establishing a logical rationale for making a
monitoring decision.
The products of the DQO process should be clear, concise statements that define the data
quality criteria and monitoring design performance specifications. These criteria define "how
good" the data should be and the degree of acceptable uncertainty in the data. These statements
identify such items as the number and locations of samples to be collected, the sampling
methods, and the analytical methods. Example 1-1 presents examples of how the DQO process
integrates with the Monitoring Plan development framework for hypothetical bioremediation and
habitat mitigation activities.
Intro-7
-------
Example 1-1 Integration of Data Quality Objectives into Development of Monitoring Plans, Verifying Success of Hypothetical
Bioremediation and Habitat Mitigation Activities
Monitoring
Framework Step
Associated DQO Step
Example 1:
Bioremediation
Example 2:
Habitat Mitigation
Step 1. Identify
Monitoring Plan
Objectives
Step 1. State the Problem.
Summarize the problem that will
require new environmental data (the
monitoring hypothesis).
Current soil contaminant of concern (COC) levels
(0-2 ft depth range) have been shown to pose
unacceptable risks to plant survival. Toxicity tests
identified mortality levels > 20% for exposed
populations, with a lowest observed adverse effect
level (LOAEL) (5% mortality) of 0.5 ppm.
Bioremediation was selected to reduce this risk to
acceptable levels. The Monitoring Plan objective is to
determine whether the bioremediation has been
successful in reducing risks to acceptable levels and
can therefore be terminated.
A 50-acre portion of a brownfield site was selected for
mitigation to tallgrass prairie. The Monitoring Plan
objective is to determine when the mitigation
activities have restored the 50-acre mitigation site to
its intended condition (tallgrass prairie).
Oo
Step 2. Develop
Monitoring Plan
Hypotheses
Step 1. State the Problem.
Summarize the problem that will
require new environmental data (the
monitoring hypothesis).
The monitoring hypothesis is that bioremediation will
reduce risks to acceptable levels by achieving soil
COC levels < 0.5 ppm in areas with COC soil
concentrations >0.5 ppm by microbial breakdown of
toxic components. On the basis of the predicted rate
of microbial breakdown, one or both of these
bioremediation goals are expected to be attained
within 7 years.
The monitoring hypothesis is that through planting,
controlled bums, and herbicide application, a tallgrass
prairie community will be established within 7 years
that will include at least 40 native plant species that
were typically present in this type of habitat in the
region of the site, with 7 target species dominating
(>50% vegetative cover) the community. Normative
species will comprise <10% vegetative cover of the
restored site.
Step 3. Formulate
Monitoring Decision
Rules
Step 2. Identify the Decision.
Identify the decision that requires
new data to address the problem.
Develop a preliminary decision rule to decide whether
the bioremediation has met its stated objectives. If
bioremediation has been successful, the management
decision may be to terminate monitoring and the
bioremediation and proceed with the relevant
regulatory process. Alternately, the decision will be to
continue bioremediation and monitoring.
Develop preliminary decision rule to decide whether
the mitigation has met its stated objectives. If
successful, the management decision may be to
terminate monitoring and the mitigation and proceed
with the relevant regulatory process. Alternately, the
decision may be to continue the mitigation activities
and monitoring.
Step 4. Design the
Monitoring Plan
Step 3. Identify Input to the
Decision. Identify information
needed to support the decision;
specify what input requires new
data.
Data needs include COC concentrations in site soils
while bioremediation is underway.
Data needs include plant community species
composition, extent of vegetative cover of the
preferred dominant plant species, and extent of
vegetative cover of normative species.
-------
Example 1-1 (Cont.)
Monitoring
Framework Step
Step 5. Conduct
Monitoring Analyses
and Characterize
Results
Step 6. Establish the
Management Decision
Associated DQO Step
Step 4. Define the Study
Boundaries. Specify the spatial and
temporal aspects of the
environmental media or endpoints
that the data must represent to
support the decision.
Step 5. Develop a Decision Rule.
Develop a logical "if. .then..."
statement that defines the conditions
that would cause the decision maker
to choose among alternative
decisions.
Step 6. Specify Limits on Decision
Error. Specify the decision maker's
acceptable limits on decision errors,
which are used to establish
performance goals for limiting
uncertainty in the data.
Step 7. Optimize the Design for
Obtaining Data. Identify the most
resource-effective sampling and
analysis design for generating data
needed to satisfy the DQOs.
Implement design optimized in
Step 7.
DQO Steps 2 and 5.
Example 1:
Bioremediation
COC data for soils in the 0-2 ft depth range will be
needed from locations where current COC
concentrations are > 0.5 ppm, and these data will be
needed on a quarterly basis for the next 6 years.
Finalize the decision rule z/the measured COC
concentrations are ^0.5 ppm and remain so for three
consecutive sampling rounds, then the remedy will be
considered successful and remediation and monitoring
can be stopped.
A 95% confidence level will be used in all statistical
evaluations of soil COC concentrations.
Develop the Monitoring Quality Assurance Project
Plan (QAPP).
Implement monitoring data collection and analysis
and evaluate monitoring data (per the DQOs and
decision rules) as they are collected.
Make a management decision based on the decision
rules developed and finalized in framework Steps 3
and 4, respectively.
Example 2:
Habitat Mitigation
Monitoring activities will be limited to the 50-acre
mitigation area; data collection will occur yearly in
late summer-early autumn for the next 7 years.
Finalize the decision rule z/the plant community
includes 40 native species, with 7 dominant species
comprising >50% and normative vegetation <10% of
the total vegetative cover of the site, then the
mitigation will be considered successful and the
mitigation and monitoring can be stopped.
Reducing data uncertainty will be based on a sample
size considered representative of the mitigation site.
Transects with a minimum 15-m spacing interval and
with plant survey locations spaced at 10-m intervals
along each transect will be considered to adequately
represent the restoration site.
Develop the Monitoring QAPP.
Implement monitoring data collection and analysis
and evaluate monitoring data (per the DQOs and
decision rules) as they are collected.
Make a management decision based on the decision
rules developed and finalized in framework Steps 3
and 4, respectively.
-------
Intro-10
-------
STEP 1: IDENTIFY MONITORING OBJECTIVES
Development of a Monitoring Plan begins with the identification of monitoring
objectives that are directly related to the expected outcome of the site activity (i.e., reduced soil
contaminant of concern [COC] concentrations, mitigation of wetland function, or long-term
stewardship of institutional controls). In Step 1, the site activity is examined and is used to
identify one or more monitoring objectives.
1.1 MONITORING OBJECTIVES
Monitoring objectives can be placed into four general categories:
• Identification of changes in ambient conditions;
• Detection of movement of environmental constituents of interest (COCs, silt,
temperature) from one location to another;
• Demonstration of compliance with regulatory requirements; and
• Demonstration of the effectiveness of a particular activity or action.
The monitoring objectives most applicable to a site activity will generally be determined
by the nature of the activity itself. In some cases, a variety of monitoring objectives may be
needed for a single site activity.
1.1.1 Examination of the Site Activity
Identification of monitoring objectives will generally be based on the examination of the
site activity, which helps to identify physical, chemical, and/or ecological parameters that could
be used later in developing the Monitoring Plan study design. Examination of the site activity
should address:
• The outcome of the site activity (what is it intended to accomplish and what
are the specific entities [e.g., biological or environmental parameters such as
community structure or contaminant concentration] expected to be affected by
the site activity?); and
• The mode of action of the site activity (how is the activity expected to meet its
intended objectives?).
1-1
-------
For activities related to contamination and risk issues, examination of the site activity
should also address:
The human health and ecological endpoints determined to be at risk at the site
(e.g., residential child, insectivorous bird); and
• The COCs and associated cleanup criteria (what are the contaminants driving
the risk, and what are the cleanup levels for reducing risks to acceptable
levels?).
The time frame for implementation, operation, and completion of the site activity (such
as a removal action or habitat restoration) should be identified to provide temporal bounds to the
monitoring objectives and subsequent monitoring studies. Activities associated with, but not
directly related to, the objectives of the site activity should be identified at this time since these
may also require consideration in the Monitoring Plan. For example, mitigation measures may be
needed to minimize environmental impacts associated with the implementation and operation of
a remedial action. These mitigation measures should be identified and evaluated to determine
whether they need to be included in the Monitoring Plan. If so, then additional monitoring
objectives specific to those measures should be developed.
Available information on the site activity may be found in a variety of sources, such as
risk assessments, decision documents, environmental characterization reports, engineering
design documents, habitat recovery plans, wetland delineations, and natural resource
management plans. For example, under CERCLA, relevant information regarding these
parameters (e.g., the COCs, endpoints at risk, etc.) can often be found in the ROD and its
supporting technical reports, such as the baseline risk assessment (BRA) and the feasibility study
(FS). Under RCRA, similar information may be found in the Statement of Basis/Response to
Comments (SB/RTC), which documents the selected corrective measure and its supporting
technical reports, such as the RCRA Facility Assessment (RFA), RCRA Facility Investigation
(RFI), and the Corrective Measures Study (CMS)
Example 1-1
Activity Outcome and Monitoring Objectives
An engineered cap has been installed at a site with two remedial outcomes: (1) to
eliminate direct exposure of human and ecological receptors to contaminated soil and
groundwater, and (2) to eliminate the potential for contaminant leaching and subsequent
groundwater transport of contaminants to off-site wetlands. For this remedial action with
two dissimilar outcomes, a single Monitoring Plan with two different monitoring
objectives would be recommended. The first monitoring objective would address the
effectiveness of the cap in reducing exposure over some designated time frame. The
second monitoring objective would address the effectiveness of the cap in controlling
contaminant transport via groundwater to off-site wetlands and groundwater.
1-2
-------
Identify the Activity Outcome: Each site activity has a unique set of physical, chemical,
and/or biological endpoints that are the target of the site activity, and these endpoints should be
considered by the monitoring objectives. For example, the target endpoints for a grassland
mitigation project may be a specified level of plant species diversity or a specific community
structure, while the target endpoint for a bioremediation project may be a specified acceptable
contaminant level in site soil. For the former example, the monitoring objective would likely be
related to demonstrating attainment of the target species diversity or community structure. For
the latter example, the monitoring objectives would be related to demonstrating attainment of a
specified COC soil concentration. Information regarding the site activity outcome and its
endpoints may also be useful during development of monitoring decision rules (see Step 3) and
in the design of specific monitoring studies (see Step 4).
Identify the Activity Mode of Action: The mode of action of an activity defines how the
activity is expected to attain its desired outcome and relates the activity endpoints to the
objectives. For example, at a CERCLA soil bioremediation project the activity objective might
be to reduce risks associated with the contaminated soil to acceptable levels, with the activity
targeting soil COC concentrations. The mode of action of the bioremediation may be the
microbial conversion of the COCs to less toxic breakdown products, thereby reducing soil COC
concentrations to acceptable levels. Monitoring objectives related to this mode of action may
focus on demonstrating that bioremediation is effectively reducing soil COC concentrations.
Information on the activity mode of action may also be useful during development of monitoring
decision rules (see Step 3) and in the design of specific monitoring studies (see Step 4). In the
case of a remedial action involving implementation of a cap, the mode of action of the cap would
be the elimination of exposure pathways to human and/or ecological receptors. The associated
monitoring objectives would focus on ensuring cap integrity, which may include compliance
with institutional controls that were established to complement the on-going physical obligations
associated with maintenance of the cap, and demonstrating that exposure is not occurring at the
site.
1.1.2 Identify Monitoring Objectives
The purpose of any Monitoring Plan is to demonstrate that a specific activity outcome has
been or is being met within some particular time frame, and to thus support a management
objective. Once information regarding the activity objectives, endpoints, and mode of action has
been examined, one or more activity-specific monitoring objectives can be identified. Table 1-1
presents examples of different types of site activities and potential monitoring objectives.
1-3
-------
Table 1-1 Example Monitoring Objectives for Different Site Activities
Site Activity
Sediment capping to reduce
contaminant exposure and
migration
Wetland mitigation
Storm water outfall
compliance with National
Pollutant Discharge
Elimination System (NPDES)
permit requirements
Bioremediation to reduce soil
contaminant concentrations
Groundwater treatment with
short-term institutional
controls to prohibit
groundwater use until cleanup
goals have been met.
Monitoring Objectives
Demonstrate that the cap is effective in reducing exposure — Has the
desired degree of exposure reduction been attained?
Demonstrate that contaminants have not migrated off site — Are
contaminants at off-site locations below preliminary remediation goals?
Demonstrate that mitigation measures enacted during remedy
implementation are successful — Are mitigation measures effective in
controlling potential impacts of remedy implementation and operation?
Demonstrate success of wetland mitigation — Have mitigation activities
achieved a desired wetland function?
Demonstrate that outfall water concentrations do not exceed levels
specified in an NPDES Permit — Are desired water concentrations being
attained?
Demonstrate effectiveness in contaminant concentration reduction — Has
a desired contaminant level been attained?
Demonstrate that treatment is effective in reducing contaminant
concentrations — Have contaminant groundwater concentrations been
reduced to desired levels?
Demonstrate that institutional controls are prohibiting groundwater use
during treatment — Has groundwater use stopped?
1.2 STAKEHOLDER INPUT
Early involvement of the monitoring team serves to identify stakeholder issues and
concerns before the objectives, decision rules, and study design of the Monitoring Plan are
finalized and implemented. The intent of early involvement is to limit future disagreements
regarding the specific design of the Monitoring Plan, thereby avoiding project delays and
associated costs.
1.3 SCIENTIFIC MANAGEMENT DECISION POINT
At the conclusion of Step 1, there is an SMDP regarding the objectives of the Monitoring
Plan. The purpose of the SMDP is to document a decision identifying one or more monitoring
objectives that best address the site activity. While a formal deliverable is not necessary, the
decision should be formally recorded as a memorandum or letter to file.
1-4
-------
STEP 2: DEVELOP MONITORING PLAN HYPOTHESES
2.1 MONITORING HYPOTHESES
Monitoring hypotheses represent statements and/or questions about the relationship
between a site activity, such as remediation or habitat mitigation, and one or more expected
outcomes for that activity. The development of the monitoring hypotheses is analogous to the
problem formulation step (Step 1) of the DQO process (Figure 1-1). The nature of the hypotheses
will strongly depend on the type of activity and the monitoring objectives previously identified
(see Step 1).
The monitoring hypothesis may be generally stated as "The site activity has been
successful in reaching its stated goals and objectives." The most basic monitoring question,
regardless of the monitoring objectives, can be stated as "Has (is) the activity of interest reached
(reaching) its stated objectives?", and the specific Monitoring Plan should focus on answering
this question. The answer to this question provides support for making a management decision
on the activity and associated monitoring, such as whether to cease the activity and monitoring
because the activity has reached its stated objectives. Examples 2-1 and 2-2 illustrate simple
monitoring hypotheses and questions for hypothetical remediation and restoration activities.
2.2 MONITORING CONCEPTUAL MODEL
Development of monitoring hypotheses may be aided by the use of a monitoring
conceptual model. The monitoring conceptual model consists of a series of working hypotheses
that identify the relationships between the site activity and its expected outcome. The model does
not need to be highly detailed or describe all aspects of the relationships between the site activity
and its expected outcome. Rather, it should describe the assumptions about the site activity and
its objectives and expected outcome and serve as the basis for the monitoring hypotheses and
questions. The answers to these questions provide the basis for making a decision on whether the
activity has reached its stated objective.
Identification of the monitoring objectives, together with the development of monitoring
hypotheses (and a monitoring conceptual model), represents the outcome of Step 1 of the DQO
process (State the Problem). Rather than summarizing a problem that requires new
environmental data, it summarizes a desired outcome that may require new data to verify
attainment of that outcome.
2.3 SCIENTIFIC MANAGEMENT DECISION POINT
The outcome of Step 2 is the identification of monitoring hypotheses and questions
specific to the site activity and development of a monitoring conceptual model identifying the
relationships between the site activity and its expected outcome. These comprise the SMDP for
Step 2. The purpose of the SMDP is to document a decision regarding monitoring hypotheses,
2-1
-------
questions, and conceptual model. The monitoring team members should agree on any subsequent
changes to these items. While a formal deliverable is not necessary, the decision should be
formally recorded as a memorandum or letter to file.
Example 2-1
Monitoring Remediation Success
This example illustrates a monitoring conceptual model, a monitoring hypothesis, and
associated monitoring questions for a remedial action addressing contaminated soil. The
remedy involves the use of bioremediation to reduce soil COC concentrations to
acceptable levels. The monitoring objectives for this activity would be to (1) evaluate the
effectiveness of the remedy in reducing soil COC levels to desired levels and
(2) determine whether and when remediation should stop, continue, or be revisited and
possibly revised.
Bioremediation to
Reduce Soil COC
Levels to Below
Threshold Levels
Soil COC Levels
Reduced to < Threshold
Levels within 5 Years
Monitoring Hypothesis'. Soil COC levels are responsible
for unacceptable soil toxicity to plants. Bioremediation
was selected as the remedy. Bioremediation produces
nontoxic breakdown products, thereby reducing soil COC
concentrations to acceptable levels within 5 years of
remedy implementation.
Monitoring Question:
1. Have surface soil (0-2 ft depth range) COC
concentrations been reduced to acceptable levels
(<0.5 ppm)?
2-2
-------
Example 2-2
Monitoring Habitat Mitigation Success
This example illustrates a monitoring conceptual model, a monitoring hypothesis, and
associated monitoring questions for a habitat mitigation activity implemented after soil
contamination was remediated by excavation and subsequent disposal of contaminated
soils. The monitoring objectives for this activity would be to evaluate the effectiveness
of the mitigation activity in restoring native prairie habitat and its biotic communities
and determining whether and when restoration should stop, continue, or be revisited and
possibly revised.
Site
Remediated by
Excavation,
Which
Eliminated
Native Prairie
Habitat
Mitigate Prairie
Habitat by Grading
Site to Original
Drainage and
Planting with
Native Vegetation
Native Plant
Community Restored
Followed by
Native Invertebrate
and Vertebrate
Communities
Desired Plant Biodiversity
and Community Structure
Attained
Desired Animal Biodiversity
and Community Structure
Attained
Monitoring Hypothesis: Soil excavation
removed COCs but resulted in the loss of
a native prairie habitat and its plant and
animal communities. To mitigate the
habitat loss, the site will be graded to its
original contours and native prairie
vegetation will be planted to reestablish
native plant and animal communities.
Monitoring Questions:
1. Have native plant biodiversity and
community structure been restored
to a desired level or condition?
2. Have invertebrate and vertebrate
biodiversity and community
structure been restored to a desired
level or condition?
2-3
-------
2-4
-------
STEP 3: FORMULATE MONITORING DECISION RULES
At the conclusion of Step 2, the monitoring objectives have been identified and
site-specific monitoring hypotheses, questions, and monitoring conceptual models have been
developed. In Step 3, preliminary monitoring decision rules are developed that relate the site
activity and the monitoring hypotheses and questions with the monitoring results. These are
refined and finalized during the development of the Monitoring Plan study design that occurs in
Step 4. These monitoring decision rules are analogous to the decision rules of the DQO process.
The data collected during implementation of the Monitoring Plan are evaluated with regard to
these decision rules, and this evaluation supports the selection of a specific management decision
(see Step 6) for the site activity and associated monitoring.
3.1 MONITORING DECISIONS
3.1.1 Formulation of Preliminary Decision Rules
In Step 3, preliminary monitoring decision rules are developed that take the form of
generalized DQO decision rules. A decision rule is an "//.. then..'' statement that defines the
conditions that would cause the decision maker to choose an action. In other words, it establishes
the exact criteria for making a choice between taking and not taking an action. In a monitoring
program, the decision rules should establish the criteria for continuing, stopping, or modifying
the Monitoring Plan and/or the site activity. In general, there are four main elements to a
monitoring decision rule:
The parameter of interest;
• The expected outcome of the site activity;
• An action level (the basis on which a monitoring decision will be made); and
• Alternative actions (the monitoring decision choices for the specified action
level).
The preliminary decision rules should be stated in general terms with regard to these
elements. Note that the preliminary decision rule does not identify specific bounds for the action
level, such as an acceptable toxicity level, a soil contaminant level, or a temporal component for
the results. These specifics should be developed during design of the Monitoring Plan
(see Step 4).
3-1
-------
Example 3-1
Preliminary Decision Rules for a Bioremediation Project
A preliminary decision rule associated with a remedial action to reduce soil COC levels
may be stated as ".//"the monitoring results indicate that bioremediation has reduced soil
concentrations to acceptable levels, then the bioremediation will be considered to have
reached its objectives and no further remedial action or monitoring will be necessary.
Otherwise, further action in the form of continued or revised remediation and monitoring
will be necessary." In this example, the preliminary decision rule identifies the parameter
of interest (soil COC levels), the site activity (bioremediation), the action level that will
serve as the basis for a decision (an acceptable soil COC level), and the alternative
actions (conclude bioremediation and monitoring or continue remediation and
monitoring).
3.1.2 Refinement of the Decision Rules
Refinement of the preliminary monitoring decision rules takes place during Step 4
(Develop Monitoring Design) (Figure 1-1). During Step 4, specific studies are identified for
addressing the monitoring hypotheses and questions; the results of these studies are applied to
the decision rules to support a site management decision. As the monitoring study design is being
developed and specific data needs and requisite studies are identified, the preliminary decision
rules are revisited and refined so they specifically relate to the monitoring studies and anticipated
results. This decision rule refinement may include the following for each parameter of interest:
• Identification of the specific monitoring study and its endpoint;
• Identification of specific action levels (such as a specified COC
concentration);
• Identification of a time frame (the site activity duration) within which the
action level is expected to be reached; and
• Identification of other monitoring study-specific factors that are directly
related to the parameter of interest (such as the spatial boundaries within
which the action levels are to be applied and the ability of available methods
to discriminate actual responses from natural variability).
For example, the preliminary decision rule in Example 3-1 may be refined as "//"the
results of a soil COC evaluation indicate that COC levels are at or below a target level, then soil
remediation will be considered to have reached its objectives and no further remedial action or
monitoring to evaluate remedy effectiveness will be necessary." In this example, the specific
monitoring study is a measurement of soil COC concentration; the study endpoint is COC
3-2
-------
concentration; the action level is a COC level at or below a target concentration; and the
alternative actions are to cease or continue remediation and monitoring.
Depending on the nature of the site activity and the monitoring goals and objectives, a
number of monitoring decision rules may be required. If the Monitoring Plan includes the
collection of several types of dissimilar data (e.g., media contaminant levels, community
structure, species diversity), the analysis of these dissimilar data may result in conflicting
conclusions. In such cases, the monitoring team should strive to predetermine how dissimilar
data will be interpreted (such as using weighting factors) with respect to one another in order to
support a site management decision. The monitoring team should also strive to ensure that the
refined decision rules are as clear and concise as possible, since these rules serve as the primary
basis for a site management decision.
3.2 SCIENTIFIC MANAGEMENT DECISION POINT
At the conclusion of Step 3, preliminary monitoring decision rules have been developed
that define the conditions that allow the decision maker to choose among alternative actions
related to the monitoring program and the site activity. These preliminary decision criteria
represent the SMDPs for Step 3. While a formal deliverable for the SMDP is not necessary, the
decision should be formally recorded as a memorandum or letter to file.
3-3
-------
3-4
-------
STEP 4: DESIGN THE MONITORING PLAN
By the conclusion of Step 3, the monitoring objectives; the monitoring hypotheses,
questions, and conceptual models; and the preliminary decision rules have been developed. This
step establishes and formally documents the goals and focus of the Monitoring Plan. In Step 4,
the data needs, data collection and analysis methods, QA/QC requirements, and final decision
rules are developed. These components of the Monitoring Plan represent the necessary
components of a U.S. EPA QAPP (as identified in the U.S EPA Quality Manual) and are fully
consistent and compliant with Agency regulations. At the conclusion of Step 4, the preliminary
decision rules from Step 3 are finalized and will be used in Step 6 to support a management
decision. Step 4 concludes with the preparation of a Monitoring QAPP, which documents the
monitoring activities that will be conducted in order to meet the monitoring objectives and
support a management decision.
4.1 IDENTIFY DATA NEEDS
A variety of data may be necessary to test the monitoring hypotheses, to answer the
monitoring questions, and ultimately to support a management decision. These data may be
chemical, physical, and/or biological in nature, depending on the hypotheses and questions, and
on the decisions to be made. Factors to consider when identifying data needs may include the
following:
• Anticipated outcome of the site activity;
• Preliminary monitoring decision rules;
• Data characteristics; and
• Applicability of data (and data collection methods) from previous site
investigations to the monitoring design.
4.1.1 Expected Outcome of the Site Activity
By considering the expected outcome of the site activity, the monitoring team can
identify the specific chemical, physical, and/or biological parameters expected to be affected by
the site activity. These parameters are the starting point for identifying the Monitoring Plan data
needs. For example, phytoremediation may be selected as a remedial action for a site having
unacceptable soil COC concentrations. The expected outcome of this action is a reduction in soil
COC concentrations to a specified level. The associated monitoring objective is to verify that the
remedial action has successfully reached that outcome. In this example, soil COC concentration
is the parameter expected to be affected by the remedial action. Potential data needs for the
monitoring program should focus on quantifying soil COC concentrations during and after the
remediation.
4-1
-------
4.1.2 Data Characteristics
Data characteristics refer to the nature and type of the data, such as a detection level or a
taxonomic level. For example, different detection levels may apply, depending on whether the
site activity involves remediation of contaminated media to reduce ecological or human health
risks. As another example, a Monitoring Plan to determine the success of a prairie mitigation
may require the collection of abundance data for a variety of species, or may focus on the
abundance of only a single indicator species. Suppose data from previous studies indicated a
plant community of about 100 species. In this example, success of the prairie mitigation may be
based on the establishment of a minimum number of those species (e.g., the presence of at least
80 of the previously identified 100 species). Alternatively, success may be based on the
abundance of a smaller subset of species that are considered indicators of desired species
associations. In both of these examples, specific data characteristics are dependent on the site
activity (i.e., remediation or mitigation) and its desired outcome (i.e., a desired media COC
concentration or a plant community), the monitoring objectives (i.e., determine whether the
activity has been successful), and the monitoring hypotheses and questions (i.e., the activity will
reduce COC concentrations or reestablish a target plant community).
4.1.3 Evaluate Applicability of Previous Investigations
During Step 1, project reports, decision documents, and other information from previous
investigations pertaining to the project site were evaluated to aid in the development of the
monitoring objectives. This same information should also be evaluated during the identification
of the monitoring data needs. Past investigations may include details regarding media and
endpoints of concern, successful environmental data collection and analysis methods, remedy
design and performance criteria, and other information that may be directly applicable to
identifying monitoring data needs. For example, data collection and analysis methods that were
successfully used in the remedial investigation (RI) to determine the nature and extent of
sediment contamination may also be appropriate for a Monitoring Plan evaluating the
effectiveness of a remedial action in reducing sediment COC concentrations. Table 4-1 provides
several examples of information from previous investigations that may be applicable to
designing the Monitoring Plan, including the identification of data needs.
4.2 DETERMINE MONITORING BOUNDARIES
The monitoring boundaries represent the "what, where, and when" aspects of the
Monitoring Plan. In defining these boundaries, the monitoring team answers the following
questions:
• What data are needed?
• How should samples be collected (discrete or composite)?
• Where should monitoring samples be collected?
4-2
-------
Table 4-1 Potential Applicability of Previous Site Investigations to the Monitoring Design
Previous
Investigation
Data Collection
Objectives
Example Studies
Data Characteristics
Potential Applicability
Remedial
Investigation
Characterize nature
and extent of
contamination
COCs measured from
groundwater wells upgradient, at,
and downgradient of the site
COCs measured in soils at the
site
COCs measured in groundwater
surface water, soil, and sediment
upgradient, at, and downgradient
of the site
Groundwater dynamics
Groundwater COC concentrations
upgradient, at, and downgradient of
the site
Surface water dynamics
Surface water COC concentrations
upstream, at, and downstream
Underlying geology and soil
associations
Soil transport and sediment dynamics
Soil and sediment COC concentrations
Methods and sampling locations
may be suitable for:
• Monitoring groundwater COC
transport;
• Monitoring changes in
groundwater quality;
• Monitoring changes in surface
water quality; and
• Monitoring changes in
soil/sediment chemistry
Baseline
Ecological Risk
Assessment
Characterize risks to
assessment endpoints
of interest
Media-based toxicity tests
Field-based plant biomass
measurements
Soil invertebrate community
structure and species abundance
Soils with different COC
concentrations
Individual species and total plant
biomass measurements
Numbers of individuals, by species
Number and types of soil invertebrates
Biotic surveys for determination
of community structure and
species abundance
Methods and sampling locations
may be suitable for:
• Monitoring changes in plant
biomass, diversity, and
community structure; and
• Monitoring recolonization of
soil invertebrates
Biodiversity
Survey
Identify current
biological
communities and
resident biota
• Physical and chemical habitat
characteristics
• Numbers of individuals, by species and
habitat
Methods and sampling locations
may be suitable for:
• Monitoring habitat mitigation
• Monitoring changes in species
abundance and community
structure
-------
• When should monitoring samples be collected?
• How long should sampling continue?
• How often should sampling continue?
The type of data to be sampled will be based largely on the data needs identified earlier in
Step 4 (see Section 4.1). For example, the monitoring data needs may be soils in the 6-12 in.
depth range, or a specific age class of fish. The geographic (spatial) area from which the
monitoring data are to be collected should be a function of the nature and objectives of both the
site activity and the Monitoring Plan. For example, if the site activity is groundwater remediation
and the monitoring objectives are to determine whether the activity has successfully reduced
groundwater COC concentrations to acceptable levels, then the Monitoring Plan would likely
include groundwater sampling from on-site, upgradient, and downgradient locations. In contrast,
if the site activity is a habitat mitigation, then sampling activities would likely be restricted to the
immediate site boundary (and reference area if available).
Once the necessary data have been identified and the spatial boundaries selected, the
temporal boundaries for the Monitoring Plan should be established. Identification of the temporal
boundaries should include information on (1) when samples should be collected (e.g., spring,
summer, dawn, dusk, etc.); (2) how often they should be collected (e.g., hourly, daily, weekly,
etc.); and (3) how long sampling should continue (e.g., 6 months, 2 years, until a specified
condition is reached).
Managers of environmental programs need to be aware that nearly all aspects of
environmental monitoring are complicated by the fact that the environment is heterogeneous at
both the macro and micro scales. Not only are environmental media such as soils or ecosystems
naturally heterogeneous, but anthropogenic effects (such as the dispersal of contaminants into the
environment) create significant spatial (and sometimes temporal) patterning and variability in the
distribution of constituents of concern. This means that generic sampling designs may easily
produce nonrepresentative, confusing, or misleading data. Generating representative data for
heterogeneous systems includes the development of a conceptual site model (CSM), which is
used to understand or hypothesize probable contaminant distributions and spatial (or temporal)
patterns in relation to the intended decisions. The CSM then guides the development of sampling
and analysis plans that will (1) test the validity of the assumptions used to develop the CSM and
(2) gather data representative of the intended decision(s). To control for the factors that introduce
variability into environmental data, sampling plans need to discuss more than just sample
locations; they must also cover "sample support" issues (sample volume, dimensions, and
particle size), sample homogenization, and subsampling procedures. In addition, commonly used
statistical techniques are most reliable when spatial patterning of targeted analytes is not present.
Since this assumption is violated under many contaminant release and migration scenarios, the
CSM is the foundation for selecting proper statistical procedures (www.triadcentral.org).
4-4
-------
4.3 IDENTIFY DATA COLLECTION METHODS
For a specific data need there may be a variety of approaches to collecting the necessary
data; some may be more costly or difficult to implement than others. For example, suppose that
the surface soil concentration of a particular metal was identified as a data need for the
monitoring program. Determining metal concentrations in soil may be quicker and less costly
using field portable x-ray fluorescence (XRF) methods than using laboratory-based Induction
Coupled Argon Plasma Spectrometry (ICAP). The most appropriate analytical method for this
example would depend on the expected activity outcome and on the monitoring objectives. If the
monitoring objective is to determine whether soil remediation has successfully reduced the soil
concentration to <100 ppm or less, the higher detection levels of the XRF may be sufficient to
gather the data needed to meet the monitoring objectives. However, if the target soil
concentration is <5 ppm, that level is below the capabilities of field portable XRF, and the more
costly and time-consuming ICAP analysis would be needed.
It is not necessary to identify specific sampling designs at this stage of study design.
Specific sampling designs are developed during optimization of the data collection design
(see Section 4.5.1). Rather, at this point, data collection methods are identified that may be
appropriate to collect the required data, and a preliminary determination is made of the feasibility
of using those approaches to collect the data with the required characteristics and within the
required time and cost restraints.
4.4 IDENTIFY DATA ANALYSIS METHODS
Monitoring, as previously defined (see Introduction), is the collection and analysis of
repeated observations or measurements to evaluate changes in condition and progress toward
meeting a management objective. It is critical that the study design and data analysis methods
can distinguish between natural variability in the data and actual response in the parameter under
evaluation. Analysis of the monitoring data may involve some form of statistical analysis. In
cases where monitoring is being conducted to identify individual exceedance of some critical
environmental conditions, statistical analysis may not be necessary. Use of an appropriate
statistical method can help support or refute the monitoring hypotheses and thus help answer the
monitoring questions. A variety of statistical tests may be employed to evaluate the monitoring
data. The specific type of tests that are deemed valid depend on the nature of the monitoring
hypotheses and questions, the data and its collection methods (percentage of nondetects, sample
size, replication, etc.), and the desired level of decision error. The selection of the statistical
approach should be based on how well the assumptions of the test are met and tied closely to the
monitoring objectives, hypotheses and questions, and decision rules. In general, analysis of the
monitoring data will employ some combination of descriptive and inferential statistics and time-
series analysis. Some common data analysis methods are described in detail in Guidance for
Data Quality Assessment (QA/G-9) (U.S. EPA 2000d); additional information may be found on
the U.S. EPA Quality System Web site (www.epa.gov/quality).
4-5
-------
4.4.1 Descriptive and Inferential Statistics
Descriptive statistical analysis of the monitoring data typically involves a determination
of the central tendency of the data, such as the mode, median, or mean, and also identification of
the dispersion (e.g., range, standard deviation) and frequency distribution (e.g., normal, bimodal)
of the data. Inferential statistics examine a set of data in order to accept or reject a specific
hypothesis. For a monitoring activity, there are two types of hypotheses that the analysis may
support: (1) the null hypothesis that the expected outcome of the site activity has been attained,
or (2) the alternative hypothesis that the expected activity outcome has not been attained.
Information on descriptive and inferential statistics can be found in a variety of sources
(e.g., Sokal and Rohlf 1981; U.S. EPA 2000d; Zar 1984).
Two types of errors are associated with the use of inferential statistics to evaluate a
hypothesis: (1) a Type I (false positive) error, or (2) a Type II (false negative) error. With a
Type I error, the analysis would indicate that the expected activity outcome has not been
achieved when in fact it has. The consequences of this type of error would be that the activity
(whether remediation or mitigation) would be deemed unsuccessful, and both the activity and its
associated monitoring program would continue. In this case, there would be no continuing risks
or impacts, but there would be a continuing expenditure of cost and effort. For a Type II error,
the analysis would support the conclusion that the expected activity outcome has been achieved
when in fact it has not, and both the activity and its associated monitoring should cease. The
effects of such an incorrect decision would be a continued potential or actual risk or impact.
Example 4-1
Hypothesis Testing and Type I and Type II Errors
The cleanup of contaminated groundwater is being carried out through the use of a
pump-and-treat system to reduce the mean groundwater concentration of lead at the
site to a mean background level. In this remediation project, the groundwater lead
concentration is measured monthly and statistically compared with the lead
concentration in groundwater collected from designated background wells. In this
example, the null hypothesis is that the mean lead concentration in the site
groundwater is not significantly different than the mean background lead
concentration. The alternative hypothesis is that the mean lead concentration in site
groundwater is significantly greater than the mean background lead concentration.
For this example, a Type I error would occur if the analysis wrongly supported a
conclusion that the mean site lead concentration was greater than the mean
background lead concentration when in fact it did not significantly differ from the
background level. With a Type II error, analysis of the data would support the
conclusion that the mean site lead concentration was not significantly different than
background when in fact it was significantly greater.
4-6
-------
Type I and Type II errors are inversely related to one another, so that the lower the
probability of a Type I error the greater the probability of a Type II error. The study design
should establish significance levels that identify the acceptable probability of making a Type I
error. In general, a significance level of 0.05 is usually considered sufficient to minimize the
likelihood of making a Type I error while not overly increasing the likelihood of a Type II error.
Although a significance level of 0.05 is among the most widely used in hypothesis testing, the
consequences of both types of errors should be considered in selecting an appropriate
significance level.
4.4.2 Trend Analysis
Trend analysis evaluates data collected at specified intervals over a specified period in
order to determine if conditions are changing over time, and if so, how they are changing
(i.e., the magnitude and direction of the change). Trend analyses can be applied to biological,
chemical, or physical monitoring data. For example, trend analysis can be used to evaluate the
rate of decline of groundwater COC concentrations under a particular remedial action, and it can
be used to evaluate the rate at which species are recolonizing a habitat restoration site.
The amount, duration, and frequency of data needed to conduct a trend analysis depend
on the nature of the data being collected and the expected outcome of the activity. For example,
the collection of groundwater data is a relatively straightforward task; the frequency of collection
is governed largely by such hydrogeological parameters as transmissivity and hydraulic
conductivity. In this example, frequent (daily or weekly) data collection may be readily possible,
and sufficient data may be collected in a relatively short period to allow for a trend analysis to be
conducted. In contrast, the collection of some types of data may be limited to only a brief period
each year. For example, suppose one was monitoring the success of a bird nesting in a habitat
mitigation site by measuring fledging success. Since nesting and subsequent fledging may only
occur yearly (i.e., during the breeding season), several years of data would be needed before any
analysis of a trend in habitat recovery and fledging success could be conducted.
Trend analysis may also be employed to predict how parameters of interest might
respond in the future, or how well an activity is progressing toward its stated objectives. The
results of such trend analyses may be used to refine or revise site activities (e.g., operations of a
particular remedial action) and thus assist future site management planning.
4.5 UNCERTAINTY ANALYSIS
Evaluation of the monitoring data must also consider the uncertainty associated with the
data. The nature and magnitude of any uncertainty may strongly affect the interpretation of how
well the data are meeting the DQO specifications, and whether the data support the decision rule.
There may be several sources of uncertainty associated with the monitoring data, such as
incomplete monitoring conceptual models, natural variation in the parameter being measured by
the monitoring program, and analytical uncertainty or variability. If the monitoring program
4-7
-------
employs the same data collection methods as those used for the RI or the BRA, then the
uncertainties identified during those investigations may also apply to the monitoring data.
4.6 FINALIZE THE MONITORING PLAN
At this point in designing the Monitoring Plan, the monitoring team should have:
• Developed monitoring objectives;
• Developed monitoring hypotheses, questions, and conceptual models;
• Formulated the monitoring decision rules;
• Identified data needs, including data characteristics;
• Determined the spatial and temporal boundaries for the data needs and data
collection activities;
• Developed decision rules and identified acceptable decision error limits; and
• Identified data analysis methods.
This information represents the DQOs developed for the Monitoring Plan by the first
six steps of the DQO process. These are the DQOs that should be met to support a defensible
monitoring decision. These DQOs also represent the preliminary design parameters for the
Monitoring Plan, identifying the why, what, when, and how aspects of data collection and
analysis for the plan.
4.6.1 Optimize the Design
During the design optimization step (Step 7 of the DQO process), sampling and analysis
alternatives are developed and reviewed with regard to satisfying the previously developed
DQOs. From those alternatives determined to best satisfy the DQOs, those that are most resource
(cost, effort) effective should be selected for use in monitoring. For example, both XRF and
ICAP approaches can be used for determining metal concentrations in soil; XRF, however, is
quicker and less costly. However, the ICAP approach provides a greatly lower level of detection.
During the optimization, a decision is made on which of these approaches or combination of
approaches would best meet the monitoring DQOs. Once an optimized monitoring design has
been completed, the data collection methods should be evaluated to ensure that they can be
successfully implemented under site conditions and within cost and budget constraints.
Optimization continues with implementation of the Monitoring Plan. As Monitoring Data are
generated and evaluated, the Monitoring Plan should be revisited to see if improvements, such as
use of a different data collection method (i.e., a newer, cheaper, faster technology) or a revised
sampling regime (i.e., a different sampling scheme) could be implemented without
4-8
-------
compromising the quality of previously collected data while continuing to meet the monitoring
DQOs. Section 5.3.2 discusses evaluating and optimizing the ongoing Monitoring Plan in
response to deviations from the monitoring DQOs.
4.6.2 Prepare Monitoring Quality Assurance Project Plan
The final aspect of developing the monitoring design is the preparation of a Monitoring
QAPP. The following should be included in this QAPP:
• An overview and general background of the site activity for which the
Monitoring Plan has been developed;
• A description of the monitoring objectives;
The monitoring hypotheses, questions, and monitoring conceptual model;
• The data needs and characteristics;
• The data collection methods, including sampling location, timing, and
frequency;
The sampling equipment and procedures;
• The data handling requirements; and
The data analysis methods.
U.S. EPA policy requires that all work performed by or on behalf of the U.S. EPA
involving the collection of environmental data shall be implemented in accordance with an
Agency-approved QAPP (U.S. EPA 2000b-c). The required components of a QAPP to be
implemented by the EPA are identified in Chapter 5 of the U.S. EPA Quality Manual in
Sections 5.3.2, 5.3.3, 5.3.4, and 5.3.5 (U.S. EPA 2000b), and the components of a QAPP to be
implemented by external organizations (e.g., EPA contractors and grantees) are identified in
EPA QA/R-5 (U.S. EPA 2001b). The Monitoring QAPP includes, and is consistent with, these
requirements and thereby satisfies the requirements of the U.S. EPA Agency-Wide Quality
System (U.S. EPA 2000c). Additional information on the required components of a QAPP, as
well as tools for assisting in its preparation, may be found on the U.S. EPA Quality System Web
site (http://www.epa.gov/quality/).
Documentation of the Monitoring QAPP may occur in a variety of ways. The QAPP that
was previously prepared and implemented in support of site characterization and risk assessment
data collection may be revised to incorporate the monitoring-specific QAPP components as
identified above. Alternately, a monitoring-specific QAPP may be prepared that focuses only on
the monitoring activities and decisions. This Monitoring QAPP may be prepared as a stand-alone
document or as an addendum to the earlier project QAPP.
4-9
-------
4.7 SCIENTIFIC MANAGEMENT DECISION POINT
The SMDP for Step 4 is the finalized Monitoring QAPP.
4-10
-------
STEP 5: CONDUCT MONITORING ANALYSIS AND CHARACTERIZE RESULTS
At the completion of Step 4, the Monitoring Plan has been developed and documented in
the Monitoring QAPP. Implementation of the plan, including data collection and analysis, occurs
in Step 5. The results of the analyses in Step 5 should be used to support a management decision
in Step 6 as to the success of both the monitoring program and the site activity under evaluation
by the monitoring program.
5.1 DATA COLLECTION AND ANALYSIS
During Step 5, all data collection activities should strictly adhere to the study design
identified in the Monitoring QAPP and be conducted at the times, locations, and frequencies
specified by the DQOs. Thus, in addition to the collection and analysis of the monitoring data, a
major component of Step 5 is the evaluation of the data, as they are collected, with regard to the
DQOs. This evaluation assists the monitoring team in determining whether the data meet the
requirements of the DQOs.
Thus, during the conduct of Step 5 the monitoring team should be continually evaluating
and interpreting the data with regard to three basic questions:
1. Do the data meet the DQOs?
2. If yes, can the data collected to date support a decision rule? or
3. If the data do not meet the DQOs, why not and what changes should be made
so that the data meet the specified DQOs?
These evaluations may be conducted as part of a data quality assessment (DQA), which
assesses the type, quantity, and quality of data in order to verify that the planning objectives,
quality requirements (consistent with the U.S. EPA Quality Manual [U.S. EPA 2000b]), and
sample collection procedures were satisfied and that the data are suitable for their intended
purpose. Guidance for conducting a DQA can be found in EPA QA/G-9 (U.S. EPA 2000d).
Depending on how well the monitoring results meet the DQO requirements, the monitoring
program may either proceed as identified in the Monitoring QAPP, be revised, or proceed to a
management decision (Figure 5-1).
5.2 EVALUATION OF ANALYTICAL RESULTS
Analysis of the monitoring data should occur as the data are generated and successfully
undergo the QA/QC data quality review as described in the Monitoring QAPP
(see Section 4.6.2). Data analyses employ the analytical methods identified in Step 4
(see Section 4.4), and the results of these analyses should be evaluated with regard to the
monitoring hypotheses, the DQOs, and the monitoring decision rules that were developed in
Steps 2 and 3.
5-1
-------
Monitoring Plan Implementation:
Data Collection and Analysis
Do the
data meet the
Monitoring Plan
DQOs?
Site Activity Assumptions
& Monitoring Conceptual
Model
Site Activity
Implementation
Revise Site Activity and
Monitoring Plan as Appropriate
(Steps 1-4)
Implement Revised Site
Activity and Monitoring Plan
(Step 5)
NO
YES
Identify
Nature of DQO
Deviation
Is the
decision rule
upported?
Resume Collection and
Analysis of Monitoring
Data (Step 5)
Monitoring Plan
Implementation
Data
Collection
Data Analysis
Revise Monitoring Plan as Appropriate,
Consistent with Monitoring Objectives and Monitoring DQOs
(Step 4)
Implement Revised
Monitoring Plan (Step 5)
Figure 5-1 Decision Path during Monitoring Implementation and Data Collection and Analysis
-------
5.2.1 Relationship of Analytical Results to the Monitoring Hypotheses
Recall that the basic monitoring hypothesis is "Has (is) the site activity reached
(reaching) its stated objectives?" (see Step 2). This hypothesis is based, in part, on specific
assumptions of how the site activity is expected to attain its outcome. As the monitoring program
generates data, the monitoring team should continually analyze those data with regard to how
well the data support the monitoring hypotheses and the underlying site assumptions as
developed in the monitoring conceptual model. Evaluation of the data may show the site activity
to be proceeding as expected, better than expected, or worse than expected. The specific outcome
determines whether any modifications or adjustments to the site activity or to implementation of
the Monitoring Plan may be appropriate.
For example, suppose a remedial action is initiated to address a contaminated soil
problem (see Example 2-1). The monitoring hypothesis may be that the selected remedy
(bioremediation) will reduce the soil contaminant concentration to <5 ppm to a specified level
within 5 years of remedy implementation. If the monitoring data indicate soil concentrations are
changing as expected, data collection would continue as described in the Monitoring QAPP.
If the data indicate better than expected response (i.e., soil concentrations are decreasing
more rapidly than expected), then the monitoring team may consider revising the Monitoring
QAPP as suggested by the data. In this case, it may be appropriate to revise not only the expected
duration of the remedy and its associated monitoring program, but also aspects of the sampling
regime related to sampling frequency. It may be possible to reduce the sampling frequency
and/or proceed to a monitoring decision and overall site management decision sooner than was
originally planned, thereby reducing overall project costs.
In contrast, if the monitoring data indicate little or no change in soil concentration, or an
increase in soil contaminant levels, then it would be appropriate to evaluate implementation of
the plan, the site activity assumptions, and/or the remedy assumptions and the monitoring
conceptual model, and identify possible revisions to the Monitoring QAPP, the remedy, or both
(Figure 5-1).
5.2.2 Data Adherence to the Data Quality Objectives
Throughout data collection and analysis, the monitoring team should pay special attention
to ensuring that the specifications established by the DQOs for the monitoring design are being
adequately met. These specifications include where and when the monitoring data are being
collected (the spatial and temporal boundaries), how the data are being collected (the collection
methods, including the sampling equipment and procedures), and how the data are being
evaluated (data analysis). The monitoring team should ensure that (1) all data collection and
analysis activities conform to the QA/QC policies and procedures identified in the Monitoring
QAPP (see Section 4.6.2), and (2) all data validations procedures identified in the plan are
carried out on all data generated by the monitoring program.
5-3
-------
5.2.3 Data Support of the Decision Rules
As the monitoring data are collected, they should be compared with the decision rules
developed in Step 3. Recall that the decision rules specify the criteria for continuing, stopping, or
modifying the monitoring program and/or the site activity. For example, a monitoring decision
rule associated with a soil contamination remedial action may be stated as "If the measured soil
contaminant concentration is less than 0.5 ppm soil for three consecutive sampling events, then
the remediation will be considered to have met its objectives." If at any point during the
collection and analysis of monitoring data the data are found to support the decision rule, then
the site would proceed to Step 6. Alternately, if the analysis indicates that the data do not support
the decision rule, then monitoring would continue as identified in the Monitoring Plan and QAPP
(Figure 5-1).
5.3 ADDRESSING DATA DEVIATIONS FROM THE MONITORING DQOs
Deviations from the DQO specifications can arise for a variety of reasons, ranging from
unexpected data collection problems, to analytical errors in the laboratory, to computational
errors during data analysis (Figure 5-1). Uncertainties associated with the monitoring conceptual
model or assumptions regarding the expected performance and outcome of the site activity may
also be the basis for deviations from the DQOs.
If deviations from the monitoring DQOs are indicated, the underlying basis for the
observed deviations should be determined. The consequences of those deviations on the success
of the site activity and on the continued conduct of the monitoring program should be
ascertained, and actions necessary to address those deviations should be identified. In general,
deviations from the monitoring DQOs may be due to (1) design and/or implementation problems
of the site activity, or (2) monitoring implementation problems. Actions to address these
deviations may include (1) changes to the design and/or implementation of the site activity,
and/or (2) changes in the implementation of the Monitoring Plan (Figure 5-1).
5.3.1 Evaluating the Site Activity
The monitoring team should examine the implementation, expected and ongoing
performance, and success of the site activity as monitoring data are collected. For example,
evaluating the performance of the remedial technology may identify operational issues that are
responsible for the DQO deviations. Examination of the monitoring conceptual model may
greatly aid in this evaluation. Recall that during early development of the monitoring program, a
monitoring conceptual model was developed to identify known and expected relationships
between the site activity and the monitoring goals and objectives (see Step 2). Once developed,
this conceptual model was then used to identify the monitoring data needs and develop the
Monitoring Plan. If the monitoring data indicate that one or more site activity assumptions are
incorrect, or that implementation of the activity is incorrect, then changes in the assumptions,
design, and/or implementation of the site activity and/or the Monitoring Plan will be necessary.
5-4
-------
Example 5-1
Revising the Site Activity
Natural attenuation was selected as the remedial action for a site having unacceptably
high contaminated soil. During the development of this remedy, the site soil was assumed
to have a particular biodegradation potential for the contaminant that would provide a
specific attenuation rate for the remedy. Monitoring data, however, indicate that soil
contaminant levels are not being attenuated at the rate expected on the basis of
biodegradation potential assumptions. In this case, the original remedial assumptions
would be revised to reflect the lower than expected biodegradation potential. A
subsequent change to the remedy design, namely the addition of soil amendments to
increase microbial activity and thus enhance biodegradation rates, was determined to be
necessary to increase the attenuation rate to the level originally assumed for the action. In
this example, there would be a revision to the remedy design, but the monitoring program
could continue as identified in the Monitoring Plan and QAPP.
5.3.2 Evaluating Implementation of the Monitoring Plan
Evaluation of the monitoring data may indicate that the observed monitoring DQO
deviations are associated with implementation of the Monitoring Plan and not with the site
activity itself (Figure 5-1). Implementation problems may be associated with one or more of the
following aspects of data collection: (1) the sampling regime, (2) the data collection methods, or
(3) the data analysis methods (Figure 5-1).
Example 5-2
Revising Implementation of the Site Activity
A herbicide program is implemented to control and eventually eradicate invasive, non-
native vegetation at a prairie mitigation site. Evaluation of the monitoring data shows
that the herbicide is not effective at the current application concentration. Large
individual plants survive the herbicide exposure, and seedlings continue to sprout within
two weeks following herbicide application. Knowledge of the effects levels of the
herbicide and its persistence in the environment suggests that success of the herbicide
program can be increased to the originally desired level through an increase, consistent
with Federal Insecticide, Fungicide, and Rodenticide Act of 1947 (FIFRA) requirements,
in the herbicide concentration and its application frequency. In this example, both the
site activity and the Monitoring Plan and QAPP would be revised.
J-J
-------
Sampling Regime: Problems with the sampling regime may be related to the spatial and
temporal boundaries of the sampling design (i.e., sampling location and frequency). The
monitoring team should examine the monitoring data, the current sampling regime, and the
nature of the DQO deviations, and determine whether changes in the sampling design would
rectify the DQO deviations. Such changes could include an increase or decrease in the number of
samples collected during each sampling event from current sampling locations, an addition or a
decrease in the number of locations sampled, or a change in the sampling location. Such changes
should be consistent with the underlying hypotheses, DQOs, and decision rules of the
Monitoring Plan and would not require changes in data collection and analysis methods.
Data Collection Methods: In some cases, evaluation of the monitoring data may show
that sampling methods are the basis for the observed data deviations from the monitoring DQO
specifications. Such a problem could result from a variety of factors, such as unexpected
environmental conditions (e.g., a greater submerged aquatic vegetation density, reducing benthic
grab sampler efficiency) or insufficient biomass availability. If such problems are encountered,
the monitoring team should determine how the data collection method could be revised or
replaced with an alternative method. In some cases, the changes may be relatively
straightforward and easy, such as simply increasing the amount of tissue collected for laboratory
analysis, or changing from one type of sediment sampler to another (e.g., Eckman dredge versus
core sampler). In other cases, a completely different sampling method may be required
(e.g., electrofishing versus gill netting). The changes in the collection methods should provide
data of sufficient quality to meet the DQO specifications and meet the needs of the decision
rules. If not, additional aspects of the Monitoring Plan, such as the monitoring goals, hypotheses,
and/or DQOs, may have to also be revised. Data collection methods may also be changed as new
technologies become available, or as alternative methods with increased efficiency and/or
reduced costs are identified.
Example 5-3
Revising the Sampling Regime
A remedial action is implemented to reduce groundwater concentrations of copper to a
level < 25 ppb within 5 years (the monitoring hypothesis). The monitoring program for
this action includes quarterly groundwater sampling. Trend analysis of the first four
quarterly rounds of data indicates that groundwater copper concentrations are decreasing
at a rate much greater than expected and may reach the target concentration (< 25 ppb)
before the next sampling period. Continuing the monitoring program with the original
sampling regime could result in remediation (and its associated costs) continuing beyond
the actual attainment of the remediation goal. In this example, it may be appropriate to
revise sampling to a bimonthly or even monthly regime until the target level has been
reached and possibly for confirmatory sampling afterwards (i.e., groundwater
concentration below the target level for four consecutive sampling periods). This would
allow for a more real-time determination of whether the criteria specified in the
monitoring decision rules have been met.
5-6
-------
Data Analysis Methods: In some cases, inability of the monitoring data to meet their
DQO specifications may be related not to sampling regime or data collection methods, but rather
to the analytical methods being employed. For example, matrix interference is a commonly
encountered problem in the chemical analysis of environmental media, and if not carefully
considered may lead to the generation of erroneous data. Similarly, confounding factors in
sediment, such as grain size or ammonia concentration, can greatly affect the outcome of
sediment toxicity analyses.
Inappropriate statistical analyses may also play a role in any observed DQO deviations.
For example, during development of a Monitoring Plan it may have been assumed that the
monitoring data would be normally or lognormally distributed, and that parametric methods for
statistical analyses would be appropriate. However, if the monitoring data are not normally
distributed, then the use of parametric analyses would produce incorrect statistical results. In this
case, the monitoring team would replace the parametric methods with a nonparametric
(distribution-free) data analysis approach.
Documenting Revisions to the Monitoring Plan: Any changes to the Monitoring Plan,
whether changes in the sampling regime, the monitoring objectives, hypotheses, the data
collection methods, or decision rules should be documented as an addendum to, or a revision of,
the Monitoring QAPP.
5-7
-------
5-8
-------
STEP 6: MANAGEMENT DECISION
6.1 MANAGEMENT DECISIONS IN THE MONITORING PLAN
In Step 6, the monitoring results are evaluated with respect to the monitoring decision
rules, and a determination is made as to how well the site activity has met its stated objectives.
Recall that the primary objective of any monitoring program is to demonstrate whether a specific
outcome (i.e., the objective of the site activity) has been (or is being) met within a specified time
frame.
If the monitoring results support the decision rules, the interpretation would be that the
site activity has successfully reached its specified outcome. In this case, the management
decision may be to discontinue both the activity and its monitoring program. For activities
involving land use controls and/or some form of containment measure (e.g., a cap), the
management decision would be to continue the activity and its associated monitoring.
Alternately, if the monitoring results do not support the decision rules, the interpretation would
be that the site activity has not been successful. In this case, the management decision would be
to determine why the activity was unsuccessful and identify what actions are necessary in order
to achieve the original site activity goals. In both cases, the management decision has
consequences that affect project costs, protectiveness of human health and the environment, and
ultimate site closeout.
6.2 GENERAL MANAGEMENT DECISIONS
At the end of the data collection, analysis, and characterization as specified in the
Monitoring QAPP, the monitoring results will point toward one of three conclusions (Figure 6-1)
relevant to the monitoring objectives and decision rules. These conclusions are:
• The monitoring decision rules have been met (results indicate site activity is
successful), or
The data are trending toward meeting the decision rules, or
• The monitoring decision rules have not been met (monitoring results indicate
the site activity has not achieved its stated objective).
The management decisions associated with each of these monitoring outcomes are
discussed in the following subsections. SMDPs and documentation associated with each
management decision are discussed in Section 6.3.
6-1
-------
Estimate Additional Site
Activity Time Needed to
Meet Decision Rule
(Based on Trend Analysis)
Management Decision:
Continue Site Activity
and Monitoring Program
(Step 5)
MONITORING
RESULTS
(from Step 5)
Are data
trending toward
meeting the
decision
rules?
Are the
decision rules
being met?
Conduct Causative Factor
and Uncertainty
Analyses
Management Decision:
Conclude Site Activity
and Monitoring Program
Prepare Decision
Document, Including
Uncertainty Description
Management Decision:
Revise Site Activity
and/or Monitoring
Program Accordingly
and Implement
(Steps 1-5)
Proceed Along
Appropriate
Regulatory Process
Figure 6-1 Monitoring Outcome Management Decision Path
-------
6.2.1 Monitoring Results Indicate Site Activity Is Successful
The most desired outcome of the monitoring program would be that the results meet the
monitoring decision rules (see Step 3), thus indicating that the site activity has reached its stated
objectives. For this outcome, the management decision may be to conclude the site activity and
associated Monitoring Plan, and move the site along in its appropriate regulatory process
(Figure 6.1).
At this stage, it is critical that the monitoring results be carefully examined with regard to
the monitoring decision rules, and especially with regard to how well the results met the
specifications of the monitoring DQOs. Uncertainties associated with the monitoring data should
be qualitatively or quantitatively identified and carefully examined. All appropriate parties
should agree that the monitoring results (and the associated uncertainty) have met the decision
rules.
6.2.2 Monitoring Results Indicate Site Activity Trending Toward Success
In some cases, while the monitoring data may not meet the decision rules indicating site
activity success (Figure 6-1), there is a strong trend in the data indicating that activity success
will likely be met sometime in the relatively near future. In this case, the site activity is simply
taking longer to meet its objectives than was anticipated during development of the monitoring
program. If a data trend toward timely activity success is indicated, the management decision
may be to continue both the site activity and the associated monitoring program (including the
Step 5 data analysis and characterization) for that time period (Figure 6-1). However, if the time
to completion is deemed too lengthy, an alternate management decision (such as an additional
removal action) may be appropriate.
6.2.3 Monitoring Results Indicate Site Activity Is Unsuccessful
If the monitoring results do not indicate site activity success, then the monitoring team
should examine all aspects of the site activity in order to identify the causative factors
responsible for the inability of the site activity to meet its stated objectives. Causative factors
may be associated with site activity implementation problems or an inappropriate activity.
Causative factors may also be associated with a number of non-activity-related issues, such as a
previously unknown contaminant source, unexpected natural variability in environmental
conditions (i.e., an extended period of drought affecting groundwater conditions or aquatic
biological communities), or unexpected natural variability in biological conditions
(i.e., unexpected disease outbreak). The monitoring team should also conduct an uncertainty
analysis to determine to what extent the uncertainties associated with the site activity and the
monitoring program may have affected the interpretation of how successful the site activity has
been (based on how well the monitoring results meet the decision rules).
Once the causative factors and potentially important uncertainties have been identified,
the monitoring team should identify the actions needed to address those factors and uncertainties.
6-3
-------
The resulting management decision could be to revise the site activity as necessary, revise the
monitoring program accordingly, and implement both (Figure 6-1).
Site activity revisions that involve actions to correct implementation problems may not
require major changes to the existing monitoring program. The monitoring team should carefully
examine the monitoring goals and objectives, decision rules, and study design to identify any
changes that may be necessary because of the proposed changes to the site activity. Once the site
activity and the monitoring program have been revised as appropriate, both would be
implemented and Step 5 data collection and analysis would continue.
Site activity revisions that entail implementation of a different site activity may or may
not require the development of an entirely new Monitoring Plan and QAPP. If the new site
activity has the same or similar objectives, then a complete revision of the Monitoring Plan
(e.g., going through the complete six-step process) would not be warranted. Rather, the existing
plan (including the monitoring hypotheses, DQOs, and decision rules) may be revised to
incorporate the new activity. A new Monitoring Plan and QAPP, including new decision rules,
would be needed only if new activity objectives are developed that are completely different from
the original activity objectives.
It is possible that the causative factors evaluation may also identify errors in the
collection and analysis of the monitoring data. Such errors should have been identified and
corrected in Step 5 as part of the DQO evaluations. However, if such errors are now found
(i.e., in Step 6), the monitoring team should correct the errors and, in the case of analytical errors
reexamine the monitoring data with regard to DQO compliance (Step 5) and meeting the
monitoring decision rules (Step 6). A subsequent management decision would then be based on
this new evaluation.
6.3 DOCUMENTATION AND SCIENTIFIC MANAGEMENT DECISION POINT
Regardless of the management decision made in Step 6, documentation of the decision
will be necessary. The specific nature of the decision document will depend on the decision
made (Table 6-1). This document serves as the SMDP for the outcome of Step 6.
6.3.1 Conclude Site Activity and Monitoring
If the management decision is to conclude the site activity and associated monitoring and
proceed along the appropriate regulatory process, the decision document should:
• Identify the management decision and the underlying decision rules on which
the decision is based;
• Summarize the monitoring data and characterization;
6-4
-------
Table 6-1 Management Decision Documentation
Management
Decision
Conclude site
activity and
monitoring
Continue site
activity and
monitoring
Revise site
activity
Replace site
activity
Management Decision
Document Components
• Management decision
• Monitoring decision rules
• Monitoring results
• Uncertainty description
• Management decision
• Monitoring decision rules
• Monitoring results,
including trend analyses
• Uncertainty description
• Management decision
• Monitoring decision rules
• Monitoring results
• Causative factor analysis
• Uncertainty description
• Suggested activity
revisions
• Management decision
• Monitoring decision rules
• Monitoring results
• Causative factor analysis
• Uncertainty description
New or Revised Site
Activity Decision
Document Needed
No
No
Yes - revised
Yes - new
New or Revised Monitoring
QAPP Needed
No
No
Yes - revised
Yes -new
Describe the uncertainties associated with the site activity, the Monitoring
Plan, and the management decision; and
Identify the monitoring team.
6.3.2 Continue Site Activity and Monitoring
If the management decision is to continue the site activity and monitoring, the decision
document should:
• Identify the management decision and the underlying decision rules on which
the decision is based;
Summarize the monitoring data, especially the analyses indicating a trend
toward activity success;
• Describe the uncertainties associated with the site activity, the Monitoring
Plan, and the management decision; and
• Identify the monitoring team.
6-5
-------
Because the decision is to continue the site activity and monitoring, no revisions would
be needed to the existing site activity decision document (e.g., the ROD) or to the Monitoring
Plan and QAPP.
6.3.3 Revise Site Activity
If the management decision is to revise the site activity, the decision document should:
• Identify the management decision and the underlying decision rules on which
the decision is based;
• Summarize the monitoring data and characterization;
• Describe the causative factor and uncertainty analyses and summarize the
results, showing as clearly as possible why the decision rules were not met
and the site activity is considered to not be successful;
• Describe the actions needed to address the causative factors and uncertainties
associated with the lack of activity success; and
• Identify the monitoring team.
If the need for a completely new site activity is identified, then the development of the
new activity will be conducted as required by the applicable regulatory process, and any
applicable documentation requirements will be applied. Development of a new monitoring
program may be necessary and would follow the six-step process described in this guidance.
If only revisions to the existing site activity are necessary, these should be documented as
required (e.g., a ROD addendum) by the applicable regulatory process under which the site
activity is being conducted (e.g., CERCLA, RCRA). Depending on the nature of the site activity
revisions, a revised Monitoring QAPP (see Step 4) may need to be prepared.
6-6
-------
BIBLIOGRAPHY
Elizinga, C., D. Salzer, and J. Willoughby, 1998, Measuring and Monitoring Plant Populations.,
BLM Technical Reference 1730-1, BLM/RS/ST-98/005+1730, Bureau of Land Management.
Sokal, R.R., and FJ. Rohlf, 1981, Biometry, 2nd ed., W.H. Freeman and Co., San Francisco,
Calif.
U.S. EPA (U.S. Environmental Protection Agency), 1988, Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA, OSWER Directive 9355.3-01, Office of
Emergency and Remedial Response, Washington, D.C.
U.S. EPA, 1989, Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual, Interim Final., EPA/540/1-89/001 A, Office of Solid Waste and Emergency
Response, Washington, D.C.
U.S. EPA, 1992, RCRA Ground-Water Monitoring: Draft Technical Guidance, EPA/530/R-
93/001, Office of Solid Waste, Washington, D.C.
U.S. EPA, 1993, Data Quality Objectives Process for Superfund, OSWER Directive 9355.9-01
(Interim Final Guidance), EPA 540/R-93-071, Office of Emergency and Remedial Response,
Washington, D.C., Sept.
U.S. EPA, 1996, "Subpart S Advance Notice of Proposed Rulemaking ('1996 ANPR')," Federal
Register 61 19432-19464, May.
U.S. EPA, 2000a, Data Quality Objectives Process for Hazardous Waste Site Investigations,
EPA QA/G-4HW Final, EPA/600/R-00/007, Office of Environmental Information, Washington,
D.C., Jan.
U.S. EPA, 2000b, EPA Quality Manual for Environmental Programs, 5360 Al, Office of
Environmental Information, Quality Staff, Washington, D.C., May.
U.S. EPA, 2000c, EPA Order 5360.1 A2, Policy and Program Requirements for the Mandatory
Agency-Wide Quality System, May. Available at: www.epa.gov/quality/qs-docs/5360-l.pdf.
U.S. EPA, 2000d, Guidance for Data Quality Assessment, Practical Methods for Data Analysis,
EPA QA/G-9, QAOO Update, EPA/600/R-96/084, Office of Environmental Information,
Washington, D.C., July.
U.S. EPA, 200la, Handbook of Groundwater Protection and Cleanup Policies for RCRA
Corrective Action, EPA/530/R-01/015, Office of Solid Waste and Emergency Response,
Washington, D.C.
Bibliography-1
-------
U.S. EPA, 2001b, EPA Requirements for Quality Assurance Project Plans, EPA QA/R-5,
EPA/240/B-01/003, Office of Environmental Information, Washington, D.C., March.
U.S. EPA, 2002, Guidance for Quality Assurance Project Plans, EPA QA/G-5,
EPA/240/R-02/009, Office of Environmental Information, Washington, D.C., Dec.
Zar, J.H., 1984, BiostatisticalAnalysis, 2nd ed., Prentice-Hall, Inc., Englewood Cliffs, NJ.
Bibliography-2
-------
GLOSSARY
Abiotic. Characterized by absence of life; abiotic materials include nonliving
environmental media (e.g., water, soil, sediments); abiotic characteristics include such
factors as light, temperature, pH, humidity, and other physical and chemical influences.
Ambient. Surrounding or background.
Assessment Endpoint. An explicit expression of the environmental value that is to be
protected or that is of primary interest.
Benthic Community. The community of organisms burrowing into, or crawling upon,
sediment at the bottom of a surface water body.
Benthic Grab Sampler. A mechanical sampler used to collect benthic organisms.
Bioassay. Test used to evaluate the relative potency of a chemical by comparing its effect
on living organisms with the effect of a standard preparation of the same type of
organism.
Biodegradation. The breakdown of a compound into more elementary compounds by the
action of living organisms, usually referring to microorganisms such as bacteria.
Biodiversity. The variety of life forms in a given area. Diversity can be categorized in
terms of the number of species, the variety in the area's plant and animal communities,
the genetic variability of the animals, or a combination of these elements.
Biomass. Any quantitative estimate of the total mass of organisms comprising all or part
of a population or other specified unit, or within a given area at a given time.
Bioremediation. Use of living organisms to clean up contamination from soil,
groundwater, or wastewater, either through conversion of the contaminants to less
harmful forms, or by the removal of the contaminants from the abiotic environment into
biological tissues.
Biotic. Living organisms, usually referring to the biological components of an ecosystem.
Brownfield. Real property, the expansion, redevelopment, or reuse of which may be
complicated by the presence or potential presence of a hazardous substance, pollutant, or
contaminant.
Cap. A cover placed over contaminated materials in order to reduce or eliminate human
or ecological exposure, prevent erosion, and/or control infiltration of water and
production of contaminant leachate.
Glossary-1
-------
Chronic Toxicity Test. A toxicity test used to study the effects of continuous, long-term
exposure to a chemical or other potentially toxic material on an organism.
Cleanup Criteria. The residual concentration of a hazardous substance in a medium that
is determined to be protective of human health and the environment under specified
exposure conditions, and that is the target of cleanup activities.
Community. Any group of organisms comprising a number of different species that co-
occur in the same habitat or area and interact through trophic and spatial relationships.
Community Structure. Refers to the composition and abundance of species within a
particular community.
Contaminant of Concern (COC). A substance detected at a hazardous waste site that has
the potential to adversely affect human or ecological receptors because of its
concentration, distribution, and mode of toxicity.
Contaminant Transport. The movement of contaminants from one location to another as
solid particles, dissolved in water, or as separate phase liquids in response to gravity
and/or movements by surface water, groundwater, or wind.
Control. A treatment in a test that duplicates all the conditions of the exposure treatments
but contains no test material. The control is used to determine the response rate expected
in the tested parameter in the absence of the test material.
Data Quality. A measure of the degree of acceptability and usability of data.
Data Validation. An analyte- and sample-specific process that extends the evaluation of
data beyond method, procedural, or contractual compliance (i.e., data verification) to
determine the analytical quality of a specific data set.
Data Validation Qualifier. Code applied to the data by a data validator to indicate a
verifiable or potential data deficiency or bias.
Dominant Plant Species. Within a given area or plant community type, the individual
species that comprise the greatest portion of the plant community, either by vegetative
cover, biomass, or abundance.
Exposure. The co-occurrence of or contact between a stressor and a human or ecological
receptor.
Habitat. The local environment occupied by an organism; place where a plant or animal
lives.
Hazard. The likelihood that a substance will cause an adverse effect under specific
conditions.
Glossary-2
-------
Hydraulic Conductivity. A number that describes the rate at which water can move
through a permeable medium.
Hypothesis. A proposition set forth as an explanation for a specified phenomenon or
group of phenomena.
Indicator Species. A species whose presence or absence is indicative of a particular
habitat, community, or set of environmental conditions.
Leaching. The process by which soluble constituents are dissolved and filtered through
the soil by a percolating fluid.
Lowest-Observed-Adverse-Effect-Level (LOAEL). The lowest level of a stressor
evaluated in a toxicity test or biological field survey that has a statistically significant
adverse affect on the exposed receptor compared with unexposed receptors in a control or
reference site.
Measurement Endpoint. A measurable biotic or abiotic parameter that is related to the
assessment endpoint.
Mitigation. May include but is not limited to restoration, remediation (bioremediation,
phytoremediation), and other environmental improvement efforts.
Mitigation Measure. Measures taken to reduce adverse impacts on the environment.
Monitoring. The collection and analysis of repeated observations or measurements to
evaluate changes in condition and progress toward meeting a management objective.
Monitoring Conceptual Model. A model that describes the relationships between the site
activity and its expected outcome, as stated in the monitoring hypotheses.
Monitoring Hypothesis. One or more statements and/or questions about the relationship
between a site activity, such as remediation or habitat restoration, and one or more
expected outcomes for the activity.
Monitoring Team. A site-specific team under the direction of site management that may
include the site manager, supporting technical staff (e.g., regional Biological Technical
Assistance Groups [BTAGs], risk assessors, environmental engineers) and appropriate
stakeholders (e.g., natural resource trustees and the public). The role of this team is to
provide input into the development and implementation of the Monitoring Plan.
Native Species. Biota that occur naturally, not as a result of human activity, in a given
area or region.
Glossary-3
-------
Natural Attenuation. Refers to naturally occurring processes in soil and groundwater
environments that act without human intervention to reduce the mass, toxicity, mobility,
volume, or concentration of contaminants in those media.
Nonnative Species. Species that humans intentionally or unintentionally introduced into
an area outside of a species'natural range.
Nonparametric. Statistical methods used when the distribution of the data is not known.
On-Scene Coordinator (OSC). The federal official responsible for monitoring or
directing responses to all oil spills and hazardous substance releases reported to the
federal government. The On-Scene Coordinator coordinates all federal efforts with, and
provides support and information to, local, state, and regional response communities.
Parametric. Statistical methods used when the distribution of the data is known.
Phytoremediation. A remediation technology using plants to remove, or to degrade to
less harmful forms, contaminants in soil, sediment, and groundwater.
Population. All individuals of one species occupying a defined area and usually isolated
to some degree from other similar (i.e., same species) groups.
Power of a Statistical Test. The probability of a statistical test to reject the null
hypothesis when in fact it is false and the alternative hypothesis is correct.
Quality Assurance (QA). An integrated system of management activities involving
planning, implementation, documentation, assessment, reporting, and quality
improvement to ensure that a process, item, or service is of a type and quality needed and
expected by the customer.
Quality Assurance Project Plan (QAPP). A document describing in comprehensive
detail the necessary QA, QC, and other technical activities that must be implemented to
ensure that the results of the work performed will satisfy the stated performance criteria
(e.g., data quality objectives).
Quality Control (QC). The overall system of technical activities that measures the
attributes and performance of a process, item, or service against defined standards to
verify that they meet the stated requirements established by the customer; operational
techniques and activities that are used to fulfill requirements for quality.
Record of Decision (ROD). A CERCLA document that states the decision on a selected
remedial action. It typically includes a responsiveness summary and a bibliography of
documents that were used to reach the decision.
Reference Site. A location as similar as possible to the site where an activity or condition
of interest is present, but lacking in that activity or condition.
Glossary-4
-------
Remedial Project Manager (RPM). Primary point of contact involved in the cleanup of
contaminated sites; coordinates, directs, and reviews the work of other agencies,
responsible parties, and contractors to ensure compliance with appropriate regulatory
requirements.
Removal Action. An action under CERCLA to abate, minimize, stabilize, mitigate, or
eliminate the release or threat of release of a hazardous substance; such actions may be
taken during any phase of the remedial action process or in the absence of a remedial
action.
Sediment. Particles that have settled through a liquid, located on the bottom of surface
water bodies and wetlands.
Site Activity. Any number of actions that could occur at a hazardous waste site, including
but not limited to, implementation and/or operation of a removal action, remedial action,
or habitat mitigation.
Soil Association. The different soil types that occur together in a specific location.
Species. A group of organisms, minerals, or other entities formally recognized as distinct
from other groups.
Species Diversity. The number, types, and relative abundance of species within an
ecosystem.
Stakeholder. Any party that has an interest ("stake") in a particular item.
Statistic. A computed or estimated statistical quantity such as the mean, standard
deviation, or correlation coefficient.
Stressor. Any physical, chemical, or biological entity that can induce an adverse
response.
Tallgrass Prairie. One of the three major types of North American Prairie, having a
landscape dominated by grasses such as big bluestem and Indian grass, as well as a large
number of other species of grasses and wildflowers, the latter called forbs. The vegetation
sometimes reaches a height of 10 ft or more.
Taxon. Any group of organisms considered to be sufficiently distinct from other such
groups to be treated as a separate unit. For example, class, order, genus, or species.
Taxonomic Level. The taxonomic category of an organism.
Toxicity. The degree of harmful effects posed by a substance to animal or plant life.
Transmissivity. The rate at which water is transmitted through a unit width of an aquifer.
Glossary-5
-------
Type I Error. Rejection of a true null hypothesis.
Type II Error. Acceptance of a false null hypothesis.
Uncertainty. Imperfect knowledge concerning the present or future state of the system
under consideration.
Upland. High land especially at some distance from water; ground elevated above the
lowlands along rivers or between hills.
Vegetative Cover. For a given area, the percentage of aerial coverage exhibited by a
particular plant species or group.
Wetland. Lands transitional between terrestrial and aquatic systems where the water table
is usually at or near the surface or the land is covered by shallow water, and having
vegetation typically adapted for life in saturated soil conditions.
Wetland Delineation. The evaluation of an area to determine whether it meets the criteria
to be classified as a wetland.
X-Ray Fluorescence (XRF). When a primary x-ray strikes a sample, the x-ray is
absorbed by the atom and becomes temporarily unstable. As the atom stabilizes, it gives
off a characteristic x-ray; each element produces x-rays at a unique set of energies that
allow nondestructive determination of the elemental composition of a sample. The
process of emissions of characteristic x-rays is called "X-ray fluorescence," or XRF.
GLOSSARY REFERENCES
Cooperrider, A.Y., RJ. Boyd, and H.R. Stuart, 1986, Inventory and Monitoring of
Wildlife Habitat, U.S. Department of the Interior, Bureau of Land Management Service
Center, Denver, Colo.
Begon, M., J.L. Harper, and C.R. Townsend, 1986, Ecology - Individuals, Populations,
and Communities, Sinauer Associates, Inc., Sunderland, Mass.
Lincoln, R.J., and G.A. Boxshall, 1987, The Cambridge Illustrated Dictionary of Natural
History, Cambridge University Press, New York, N. Y.
Suter, G.W., II, 1993, Ecological Risk Assessment, Lewis Publishers, Chelsea, Mich.
U.S. EPA (U.S. Environmental Protection Agency), 1997, Ecological Risk Assessment
Guidance for Superfund: Process for Designing and Conducting Ecological Risk
Assessments, Interim Final, EPA 540-R-97-006, Environmental Response Team, Edison,
N.J., June 5.
Glossary-6
-------
U.S. EPA, 2002a, Guidance on Environmental Data Verification and Data Validation.,
EPA QA/G-8, EPA/240/R-02/004, Office of Environmental Information, Washington,
D.C., Nov.
U.S. EPA, 2002b, Policy and Program Requirements for the Mandatory Agency-Wide
Quality System, EPA Order 5360.1 A2, May. Available at: www.epa.gov/quality/qs-
docs/5360-l.pdf.
Glossary-7
-------
Glossary-^
------- |